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Journal of Psychiatric Research 46 (2012) 346e352

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Journal of Psychiatric Research

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Life history of impulsive behavior: Development and validation of a newquestionnaire

Emil F. Coccaro*, Catherine A. Schmidt-KaplanClinical Neuroscience & Psychopharmacology Research Unit, Department of Psychiatry, MC# 3077, The University of Chicago, 5841 South Maryland Avenue, Chicago, IL 60637, USA

a r t i c l e i n f o

Article history:Received 20 October 2011Received in revised form14 November 2011Accepted 15 November 2011

Keywords:ImpulsivityBehaviorInterviewQuestionnairePersonalityAggression

* Corresponding author. Tel.: þ1 773 834 4083; faxE-mail address: ecoccaro@yoda.bsd.uchicago.bsd.u

0022-3956/$ e see front matter � 2011 Published bydoi:10.1016/j.jpsychires.2011.11.008

a b s t r a c t

A self-report version of the Lifetime History of Impulsive Behaviors (LHIB) interview was developed andits psychometric properties examined. Initially, forty-two personality disordered and 20 control subjectscompleted both the interview (I) and self-report (Q53) versions of the LHIB along with other self-reportmeasures of impulsivity and an assessment of venturesomeness and empathy.The LHIB-Q53 demon-strated good to excellent internal consistency, test-retest reliability, and evidence of convergent anddivergent validity. The LHIB-Q53 was then simplified to 20 items and administered to a large population-based sample of adults from the community. Following this, it was administered to nearly 400 subjectswith or without histories of Axis I and/or II disorders. The latter two studies demonstrated good toexcellent psychometric properties as well as evidence of convergent and divergent validity. Since theLHIB quantifies the occurrence of impulsive behaviors, rather than a self-assessment of a personality traitof impulsivity, we propose that the LHIB-Q20 represents a needed additional assessment of impulsivityfor behavioral science research.

� 2011 Published by Elsevier Ltd.

1. Introduction

The assessment of impulsivity has increasingly gained attentiondue to the observed relationship between impulsivity and manybehavioral disorders. Initially, an interview assessment of impul-sivity, the Lifetime History of Impulsive Behavior (LHIB), wasdeveloped to assess impulsive behaviors, especially thoseresulting in clinically significant distress and/or impairment(Schmidt et al., 2004). Although the psychometric properties of theLHIB interview are encouraging, an interview assessment is bothcumbersome and expensive to administer and thus, a simpler,questionnaire-based assessment may be of greater utility providedthat it maintains the psychometric properties of the interviewassessment.

Currently, the most commonly used psychometric assessmentsof impulsivity are the Barratt Impulsiveness Scale (BIS; Patton et al.,1995), now in its 11th revision, and the Impulsiveness Scale of theEysenck Personality Questionnaire-II (I7; Eysenck, 1993). Both areself-rated questionnaires that are, as expected, intercorrelated.Both assess impulsivity as a personality trait but not from a clinicalor historical perspective. In contrast, the LHIB was designed to

: þ1 773 834 4536.chicago.edu (E.F. Coccaro).

Elsevier Ltd.

assess the frequency of actual impulsive behaviors over the adultlifespan rather than a self-assessment of how impulsive one mightbe. Other assessments of impulsivity have also been proposed andstudied, however, these are either embedded in larger psycho-metric personality assessments or are based on laboratory assess-ments of behavioral phenomena thought to reflect various aspectsof impulsivity. Therefore, a self-report version of the LHIB washypothesized to provide a quick and efficient means of gatheringthis significant and unique data on impulsive behavior itself.

The purpose of the first half of this report was to create andexamine the psychometric properties of a self-report version of theLHIB interview. The second half of this report extends the first,creating a more simplified and concise measurement which retainsthe same or demonstrates better psychometric properties.

The self-report version of the Lifetime History of ImpulsiveBehaviors is based upon the definition of impulsivity and the itemsoriginally developed for the interview version. Impulsivity, in thiscontext, is defined as a predisposition to act (or to fail to inhibita behavior) when faced with the possibility of obtaining aninstantaneous reward or positive stimuli of some sort, with onlyminimal cognitive processing regarding to potential later difficul-ties. To be clinically significant, this type of processing results in theexecution of behaviors which ultimately yield personal, interper-sonal, and/or social difficulties. The initial self-report version of theLHIB was intended to parallel the interview version in format and

E.F. Coccaro, C.A. Schmidt-Kaplan / Journal of Psychiatric Research 46 (2012) 346e352 347

content. The items developed for both the interview and self-reportversions include a range of behaviors likely to occur in a variety ofcontexts. As noted by Olson (1989), the motivational, emotional,and attributional factors inherent in the process of behavingimpulsively all need to be considered and, therefore, these factorswere included in the development of items and/or follow-upquestions; motivations for behaviors are queried. Finally, due tothe developmental nature of impulsiveness and the fact thatchildhood impulsiveness may differ from adult impulsivity(Schachar and Logan, 1990; Thompson and Elliot, 1983; Heaven,1991; Costantini et al., 1973), the LHIB was created as a measureof impulsive behavior in adults.

2. Methods and study-by-study results

2.1. Study Ia: development of the LHIB questionnaire

2.1.1. IntroductionIn Study Ia, a 53-Item questionnaire (LHIB-Q53) version of the

LHIB-Interview was developed. Its psychometric properties inhuman subjects was tested in Study Ib.

2.1.2. Methods: development of the life history of impulsivebehavior-self-report

The self-report version of the LHIB (LHIB-Q53) initially consistedof 79 items and was based on the 40 items of the LHIB-Interview(Schmidt et al., 2004), in turn, based upon a review of the impul-sivity literature that identified critical incidences or extremes ofbehaviors believed to reflect impulsiveness. A collection of itemsspanning awide range of behaviors likely to occur across a variety ofdomains (including emotionally-charged situations) were devel-oped. Each interview item was altered, either by making it morespecific or revising it in suchamanneras tomake itmore appropriatefor the self-report format. Once the items were drafted, up to nineclinician-raters (psychiatrists and clinical psychologists at either themaster’s or doctoral level) reviewed the questions for accuracy,wording, grammar, ambiguity, appropriateness or relevance to testspecifications, technical item construction problems, appearance ofbias, and level of readability. As an effort to support content validityof the items, the clinician-raters were asked to respond using a four-point scale (Poor, Fair, Good, Excellent) to describe the qualityof eachitem as reflective of impulsivity. Content validity of the items wasalso achieved through careful conceptualization and wording andassessed through evaluation by an expert panel of ten researcherspublished in impulsivity and impulsivity-related behaviors(see Acknowledgments). Revisions were thenmade based upon thisfeedback. For each item, the subject indicated the frequency of thebehavior across his/her adult lifetime, using afive point scale rangingfrom “no events” to “more times than can be counted” (Appendix) asused in the LHIB Interview (Schmidt et al., 2004). Consequences areassessed by asking the subject to identify behaviors that resulted innegative outcomes (i.e., “Did it cause trouble?”& “Were you upset ordistressed?”). Similar to those scores obtained with the interview,the self-reportmeasure yields three scores: a) Total impulsivity score(IMP) based on the number of times the individual engaged inimpulsive behaviors, b) clinically significant impulsivity score (CSI),summing the number of times the subject performed behavior thatled to distress or impairment, and c) non-clinically significantimpulsivity score (NCSI) reflecting the frequency of impulsivebehaviors which did not result in difficulties.

The initial version of the LHIB-Q53 was then administered toabout ten staff volunteers in order to identify general difficultieswith the structure and content of the items. Further revisions weremade based on this feedback. Next, the LHIB-Q53 was administeredto twenty-two volunteer subjects, similar to those described for the

development of the Interview version of the LHIB (Schmidt et al.,2004), in order to perform preliminary statistical analysis of theitems. After completing the LHIB-Q53, subjects were debriefedregarding the nature of the project and asked for reactions, specif-icallywith regard to the comprehensibility of questions and theflowof the self-reportmeasure. After this, a fewadditional revisionsweremade. Item analysis included: 1) the distribution of responses toeach item (between 10% and 90% of the samplemust have endorsedthe item and responses must have ranged three points or more onthe six-point scale in order to be retained), 2) itemdiscrimination, orthe degree of relationship between the item response and the totalmean score on the measure (Spence et al., 1990) between the itemand either IMP or CSI total scores, and 3) ratings by clinician-raters(rated at least 1.75, in between the “fair” and “good” ratingmarkers on the four-point scale). If more than two self-report itemsparalleling any given interview item met the minimum criteria forinclusion, only the two best self-report items were retained. Deci-sionsweremade conservatively,with the idea thatwith the additionof new data and further revisions, the scale would be improved asadditional items were deleted. Lastly, final revisions and proof-reading of the self-report instrument were completed.

2.1.2.1. Results. Nine items were removed from the self-reportversion based upon feedback from the clinician-raters and staffvolunteers. A few items were combined into new items and almostall others underwent revisions. After revisions were made, the self-report consisted of 70 items. Based upon item analyses of data, anadditional 17 items were dropped either because they did not meetthe minimum criteria for retention or because there were multipleitems matched to the same interview item, in which case only thebest of these items were retained. All other items (n ¼ 53) wereretained for inclusion in Study Ib.

2.2. Study Ib: reliability and validity for the LHIB-Q53

2.2.1. IntroductionThis study was conducted to explore the psychometric proper-

ties and performance of the LHIB-Q53 in a modest-sized group ofvolunteers with andwithout a current or lifetime history of Axis I orAxis II disorders.

2.2.2. Methods2.2.2.1. Subjects. 62 subjects participated in Study Ib (n¼ 43males;n ¼ 19 females). These subjects ranged in age from 21 to 58 years(mean: 35.5 � 9.4). Subjects were drawn from those recruited fora larger study designed to assess healthy and psychiatricallydisordered subjects with regard to impulsive aggressive and relatedbehaviors. Subjects were recruited through newspaper and publicservice announcements and/or clinical referral. Subjects wereassessed using the Structured Clinical Interview for DSM-IV Axis IDisorders (SCID), and the Structured Interview for DSM-IVPersonality (SIDP-IV), as previously described (Coccaro et al.,2010). Criteria for exclusion from the study included a current orpast psychotic or bipolar disorder, current alcohol and/or drugdependence, or mental retardation. Written informed consent wasobtained prior to participation in the study. Forty-two of thesubjects were diagnosed with an Axis I and/or an Axis II disorder(Psychiatric Subjects: PS) and 20 showed no evidence of any Axis Ior Axis II disorder (Normal Control Subjects: NC). A subset of thesesubjects (n ¼ 37) also participated in the test-retest phase of thestudy, completing the LHIB-Q53 a second time. Finally, an addi-tional 30 subjects (either a first-degree relative or close friend ofthe proband subject) participated as informants, and completed theLHIB-Q53 to explore the degree of correlation between the resultsfrom the subject and the informant.

E.F. Coccaro, C.A. Schmidt-Kaplan / Journal of Psychiatric Research 46 (2012) 346e352348

2.2.2.2. Measures. All subjects were administered the LHIB-Q53 inaddition to other selected assessments of impulsivity and otherpersonality constructs. Measures of impulsivity included theInterview Version of the LHIB (LHIB-I), the development, reliability,and validity of which was detailed in a previous publication(Schmidt et al., 2004) and the Barratt Impulsivity Scale-11 (BIS-11;Patton et al., 1995). Eysenck Personality Questionnaire-2 (EPQ-2)scales for Venturesomeness and Empathy were included to furtherassess convergent and divergent validity. EPQ-2 Venturesomenessis thought to represent a form of risk-taking impulsivity and EPQ-2Empathy is thought to represent a person’s ability to understandthe emotional feelings of others (Eysenck and Eysenck, 1975). SinceEPQ-2-Venturesomeness is a mixed construct in terms of impul-sivity (Eysenck and Eysenck, 1978), we hypothesized that EPQ-2-Venturesomeness would correlate with LHIB-Q53 Impulsivityscores but to a lesser degree than the primary impulsivity measure,BIS-11 Impulsivity. Since EPQ-2-Empathy represents a constructorthogonal to impulsivity, we hypothesized that EPQ-2-Empathywould not correlate with LHIB-Q53 Impulsivity scores.

2.2.2.3. Procedures. In random order, subjects completed the LHIB-I, LHIB-Q53, BIS-11, and EPQ-2 assessments. Informant interviewswere conducted on a different day, blind to the results of the LHIB-I,LHIB-Q53, BIS-11, and EPQ-2 results. Internal consistency of theitems was assessed using Cronbach’s alpha. Test-retest reliabilitywas assessed through examination of scores obtained from the firstand second administration (Mean: 12.8 � 10.7 days; Range: 5e69days) and using paired t-tests and Pearson correlation coefficient.Empirical evidence of construct validity was obtained through anexamination of concurrent and divergent validity. Three types ofanalyses were performed: 1) concurrent validity through correla-tion between the LHIB-Q53 and the LHIB-I and the BIS-11 Impul-sivity scale, 2) concurrent validity through examination of scoresbetween groups posited to differ in impulsivity (i.e., NormalControls vs. Psychiatric Subjects), and 3) divergent validity throughcorrelation between LHIB-Q53 and EPQ-2-Venturesomeness andEPQ-2-Empathy which were hypothesized to be less than thosebetween LHIB-Q53 and BIS-11.

2.2.3. Results2.2.3.1. Administration time. The mean time to complete the LHIB-Q53 was 16.9 � 5.7 min. There were no significant differencesbetween the diagnostic groups with regard administration time(F[2,10] ¼ 1.407, p ¼ .30).

2.2.3.2. Internal consistency and test-retest reliability. The LHIB-Q53demonstrated a very high alpha coefficient (a ¼ . 96). Raw scores atretest were significantly lower for Total Impulsivity (IMP:92.5 � 46.8 vs. 84.7 � 45.7, t35 ¼ 2.11, p < .001) and ClinicallySignificant Impulsivity (CSI: 50.8 � 44.1 vs. 44.5 � 42.9, t35 ¼ 2.76,p < .001), but not for Non-Clinically Significant Impulsivity (NCSI:42.3 � 23.3 vs. 40.7 � 23.4, t35 ¼ .48, p ¼ ns). Despite these smallreductions (4e12%) between administrations, test-retest reliabilitycorrelation coefficients were high and statistically significant forIMP (r ¼ .88, p < .001), CSI (r ¼ .86, p < .001), and for NCSI (r ¼ .60,p < .001). Informant LHIB-Q53 scores demonstrated a significantcorrelationwith the subject’s LHIB-Q53 for Total Impulsivity (r¼ .61,p < .001) and Clinically Significant Impulsivity (r ¼ .50, p < .01) butnot for Non-Clinically Significant Impulsivity (r ¼ .30, p ¼ ns).

2.2.3.3. Concurrent validity. A highly significant correlation wasseen for Total Impulsivity scores from the LHIB-Q53 and the LHIB-I(r¼ .80, n¼ 62, p< .001). In addition, a similar correlationwas seenfor Clinically Significant Impulsivity scores on the LHIB-Q53 and theLHIB-I (r ¼ .77, n ¼ 62, p < .001). Non-Clinically Significant

Impulsivity scores on the LHIB-Q53 also correlated significantlywith those on the LHIB-I but this correlation was much smaller(r ¼ .37, n ¼ 62, p < .001). LHIB-Q53 Total Impulsivity (r ¼ .57,n ¼ 62, p < .001), and Clinically Significant Impulsivity (r ¼ .57,n ¼ 62, p < .001), scores were equally correlated with TotalImpulsivity on the BIS-11. In contrast, Non-Clinically SignificantImpulsivity displayed no correlation with Total Impulsivity on theBIS-11 (r ¼ .06, n ¼ - 62, p ¼ .668). As expected, psychiatric subjectshad significantly higher LHIB-Q53 scores for Total Impulsivity(110.5 � 42.7 vs. 54.7 � 29.3, t60 ¼ 5.27, p < .001) and ClinicallySignificant Impulsivity (68.2 � 42.7 vs. 14.3 � 14.6, t56.3 ¼ 7.32,p < .001) but not for Non-Clinically Significant Impulsivity(42.3 � 26.1 vs. 40.4 � 21.7, t60 ¼ .28, p ¼ .781).

2.2.3.4. Divergent validity. The correlation between LHIB-Q53 TotalImpulsiveness and EPQ-2 Venturesomeness was modest andmarginally statistically significant (r ¼ .27, n ¼ 62, p ¼ .033). Whenexamined in a multiple regression model with BIS-11 Impulsivityscores, the part correlations between LHIB-Q53 and BIS-11 Impul-sivity and EPQ-2 Venturesomeness were .56 (r2 ¼ .314) and .26(r2 ¼ .068), respectively. This indicates that BIS-11 Impulsivityuniquely accounts for nearly five times the overlapping variancewith LHIB-Q53 Impulsivity than does EPQ-2 Venturesomeness.EPQ-2 Empathy correlated with LHIB-Q53 Impulsivity scores atonly a trend level of significance (r ¼ .22, n ¼ 62, p ¼ .092). Whenexamined in a multiple regression model with BIS-11 Impulsivityscores, the part correlations between LHIB-Q53 and BIS-11 Impul-sivity and EPQ-2 Empathy were .54 (r2 ¼ .292) and .14 (r2 ¼ .020),respectively. This indicates that BIS-11 Impulsivity uniquelyaccounts for nearly fifteen times the overlapping variance withLHIB-Q53 Impulsivity than does EPQ-2 Empathy.

2.2.4. Discussion of Studies Ia and IbThese studies focused on the development of the LHIB-Q53 and

examined both the reliability and the validity of the instrument.The LHIB represents the only self-report assessment tool ofimpulsivity that specifically, and individually, divides impulsivebehaviors into those resulting in distress and/or impairment fromthose that cause no difficulties. It also provides a total impulsivityscore. Data supports that the LHIB-Q53 is both a reliable and validmeasure of impulsivity.

Content validity, including content coverage and relevance, isachieved through the careful practice and the theoretical exami-nation of the items. In Study Ia, experts were asked to rate eachitem to the degree to which it might accurately reflect impulsivity,based upon the experts’ knowledge. Any item rated belowthreshold was removed. Any item included in Study 1b, therefore,had already been rated as relevant for inclusion in a behavioral/cognitive measure of impulsivity. Construct validity was examinedin Study 1b and is supported through a number of empirical anal-yses which aimed to demonstrate that the test measures theconstruct it is intended to assess.

The LHIB-Q53 demonstrates acceptable test-retest reliability.Additionally, all scales produced high levels of internal consistency.It may be argued the scale is too internally consistent or possiblyredundant. However, careful examination of the items will quicklyreveal that the LHIB-Q53 consists of items tapping several differentbehaviors occurring in various situations and settings. Because ofthe efforts made toward content validity in the early writing of theitems, it does not appear that the high alpha levels are a merereflection of redundancy.

Overall, scores on both versions of the LHIB highly correlate withone another, suggesting strong similarity between the interviewandself-report versions.Mean scores on the LHIB-Q53 are slightly higherthan scores on the interviewversionof themeasure. This is likely due

E.F. Coccaro, C.A. Schmidt-Kaplan / Journal of Psychiatric Research 46 (2012) 346e352 349

to the fact that the self-report consists of a greater number of itemsthan does the interview, allowing for higher scores. Scores on bothversions followed a similar pattern, however, with CSI scoresapproximately 60% (64% for the interview, 54% on the self-report) ofIMP scores, and CSI scores greater thanNCSI scores for both versions.On both the interview and self-report versions, differences betweenDistress and Impairment scores were not significant.

Group differences between the normal control subjects and thepsychiatric subjects were obtained with the LHIB-Q53, suggestingthat it is capable of capturing differences in IMP and CSI by diag-nostic grouping. It was hypothesized that subjects diagnosed witha psychiatric disorder would be more likely to have behaved in animpulsive manner more frequently and to have associated withthose behaviors greater incidence of distress and impairmentrelative to those classified as normal controls. Thus, these findingsoffer evidence of the measure’s construct validity.

Criterion-related, or concurrent validity, is based on the test’sassociation with other measures given at the same time (Messick,1975, 1980). All scores except NCSI obtained from LHIB-Q53demonstrate a moderate, positive association with impulsivityscores obtained on the BIS-11. Therefore, the LHIB-Q53 appears tobe measuring a construct similar to that assessed by the BIS-11. Allinformant scores evidenced moderate correlations with subjectreports, suggesting subjects are reporting accurately.

The relationship between the LHIB-Q53 with EPQ-2 Venture-someness, especially when examined with regard to the BIS-11,suggests that the LHIB-Q53 is assessing impulsivity rather thanventuresomeness, offering evidence of the divergent validity of themeasure. Further, the lower association between the LHIB-Q53 andempathy and the partial correlations obtained using the BIS-11demonstrate a much stronger relationship between the LHIB-Q53and impulsivity rather than empathy, strengthening the case thatthe LHIB-Q53 is a valid assessment of impulsivity.

The LHIB-Q53 can be completed within reasonable time limits;however, if the measure could be completed more quickly it couldbe a very economical assessment of impulsive behavior and be ofvalue in many studies, especially studies with a large battery ofassessment measures. Studies II and III were aimed at this purpose.

2.3. Study II: revision to a 20 item LHIB-Q and reliability andvalidity for LHIB-Q20 in a population sample of over 1500 adults

2.3.1. IntroductionIn Study II, the LHIB-Q53 was revised to a simpler and shorter

form with only 20 items and only one response required per item.After revision, the psychometric properties and performance of theLHIB-Q20 was explored in a large group of population-basedsubjects.

2.3.2. Methods2.3.2.1. Revision of the LHIB-Q53 to the LHIB-Q20. Item-to-totalscore correlations for the LHIB-Q53 from the data in Study Ibrevealed 20 items with a Pearson correlation coefficient of >.50(Mean: r ¼ .66 � .05; Range: r ¼ .56 to .72, p < .001). These itemswere then retained in a revised LHIB-Q20 questionnaire. Because ofthe high correlation between Total Impulsivity and ClinicallySignificant Impulsivity scores on the LHIB-Q53 (r ¼ .85, n ¼ 62,p< .001), and because Non-Clinically Significant Impulsivity did notcorrelate with a standard measure of impulsivity (BIS-11) and didnot differ among healthy controls and psychiatric patients in StudyIb, questions about clinical significance (i.e., whether impulsivebehavior was associatedwith distress or impairment) were droppedyielding a sole Impulsivity score and making the LHIB-Q20 evenbriefer and less complicated to complete. Examining the LHIB-Q20items, using the Study 1b data set, the LHIB-Q20 had very good

internal reliability (Cronbach alpha ¼ .94), good test-retest reli-ability (r ¼ .86, n ¼ 29, p < .001), and a high correlation with theLHIB-Interview (r ¼ .76, n ¼ 54, p < .001) suggesting that the LHIB-Q20 might have as good a psychometric profile as the LHIB-Q53 inStudy 1b. The next stepwas to examine the psychometric propertiesof the LHIB-Q20 in an independent sample.

2.3.2.2. Subjects. 1561 subjects participated in Study II (Males: 652;Females: 909). These subjects ranged in age from 18 to 52 years(Mean: 33.2 � 6.2). Subjects were randomly drawn from the PennTwins cohort (Coccaro and Jacobson, 2006) with the constraint thatall the subjects in Study II analyses were unrelated. Most subjectswerewhite (White: 93.5%; African-American/Hispanic: 3.9%; Other:2.6%), employed (90.6%), and came fromhouseholds with an annualincome of $25,000 or higher (88.6%). Because screening questionsregarding behavioral disorders were included in the overall ques-tionnaire packet, subjects were also divided into those with(n ¼ 427) and without (n ¼ 1134) a life history of mood, anxiety,anger, or substance use disorders. Written informed consent wasreviewed with all subjects and subjects’ signatures were obtainedon consent forms prior to participating in the study.

2.3.2.3. Measures. Subjects completed the LHIB-Q20 and otherquestionnaire measures of impulsivity, aggression, neuroticism,and extraversion. Self-report impulsivity was measured by theBarratt Impulsivity Scale (BIS-11; Patton et al., 1995). Aggressionwas assessed by the Life History of Aggression (LHA; Coccaro et al.,1997). Neuroticism and Extraversion was assessed by the EysenckPersonality Questionnaire-Short Form (Eysenck and Eysenck,1964). A subgroup of 140 subjects were asked to complete theLHIB-Q20, again, about eight to ten months after completing it thefirst time.

2.3.3. Results2.3.3.1. Administration time. Study III was conducted by mail and,thus, no data was available regarding the length of time it took forsubjects to complete the LHIB-Q20.

2.3.3.2. Internal consistency and test-retest reliability. The Cronbachalpha coefficient for the LHIB-Q20 was as high as in Study Ib(a¼ .92) and did not differ as a function of subjects having (a¼ .92),or not having (a¼ .92), a history of psychiatric problems. There wasa small, non-statistically significant, reduction in LHIB-Q20Impulsivity scores from Time 1 to Time 2 (40.6 � 10.1 vs.38.9 � 18.4, t139 ¼ 1.64, p > .10) and the test-retest correlation washigh at r ¼ .79 (n ¼ 140, p < .001).

2.3.3.3. Concurrent validity. LHIB-Q20 Impulsivity scores werecorrelated with BIS-11 Impulsivity scores (r ¼ .51, n ¼ 1565,p < .001). Multiple regression analysis revealed that each BIS-11Impulsivity subscale contributed uniquely to LHIB-Q20 scores(R ¼ .52, R2 ¼ .27, F[3, 1550] ¼ 186.34, p < .001; Motor Impulsivity:part r ¼ .23; Attentional Impulsivity: part r ¼ .13; Non-PlanningImpulsivity: part r ¼ .19, all p < .001). As expected, LHIB-Q20scores were significantly higher in individuals with a self-reported history of psychiatric problems: Positive PsychiatricHistory (49.9 � 18.8) vs. Negative Psychiatric History (40.1 � 17.6,t1559 ¼ 9.65, p < .001).

2.3.3.4. Correlations with related constructs and divergent val-idity. LHIB-Q20 scores correlated directly with LHA Aggressionscores (r ¼ .46, n ¼ 1558, p < .001). While LHIB-Q20 scores corre-lated directly with EPQ-1 Neuroticism scores (r ¼ .38, n ¼ 1561,p < .001), LHIB-Q20 scores were not correlated with EPQ-1 Extra-version scores (r ¼ �.02, n ¼ 1561, p > .45).

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Healthy Axis I Axis II IED-IR

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Fig. 1. Mean (�SEM) scores on the LHIB-Q20 scores for healthy controls, Axis ISubjects, Axis II subjects, and IED-IR subjects. LHIB-Q20 scores for Axis I Subjects arenot different from those of healthy controls (NS). LHIB-Q20 scores for Axis II (*) andIED-IR subjects (**) are higher than those of both healthy controls and Axis I Subjects.LHIB-Q20 scores of IED-IR subjects (**) are higher than those of Axis II subjects.

E.F. Coccaro, C.A. Schmidt-Kaplan / Journal of Psychiatric Research 46 (2012) 346e352350

2.3.4. Discussion of Study IIIn Study II, thirty-three items, as well as the subscales of the

LHIB-Q53, were removed to create a more concise scale of impul-sivity. Analysis of the new 20-item scale in a sizable population-based sample, indicate that the LHIB-Q20 is also an internallyconsistent instrument with good test-retest reliability. Similar tothe LHIB-Q53, scores were reduced upon second administration,but the difference was insignificant. Examining the LHIB-Q20 withother scales provides evidence of construct validity, as demon-strated by correlation with scores on the BIS-11. Further support isoffered by the fact that subjects who self-report psychiatric histo-ries tend to score higher on this measure of impulsive behavior.

The LHIB-Q20 shows significant association to both ameasure ofaggression and one of neuroticism, but to a lesser degree than thatnoted with impulsivity. This is expected as aggression oftenincludes an element of impulsivity and neuroticism reflects mentalhealth. The LHIB-Q20,however, does not demonstrate an associa-tion with extraversion, offering additional support for divergentvalidity.

2.4. Study III: the LHIB-Q20 in a clinical research sample of adults

2.4.1. IntroductionIn Study III, the psychometric properties and performance of the

LHIB-Q20 was explored in a group of nearly 400 subjects engagedin clinical research studies of personality and impulsive aggression.

2.4.2. Methods2.4.2.1. Subjects. The LHIB-Q20was administered to 379 subjects inongoing clinical research studies of impulsivity and aggression atthe University of Chicago. 178 of the subjects were male and 201were female and ranged in age from 18 to 65 years (Mean:35.2 � 9.9 years). Most subjects were white (White: 55%; African-American: 33%, Other: 12%), employed (59.2%), and most camefrom the middle two Hollinghead Socioeconomic Classes II and III(SES I ¼ 12.4%; II ¼ 48.3%; III ¼ 17.9%; IV ¼ 10.6%; V ¼ 10.8%).Written informed consent was obtained from all subjects prior toparticipating in the study. The method of diagnostic assessment ofthese types of subjects has been detailed in previous reports(Coccaro et al., 2010). Overall, 92 subjects were found to be free ofany current or life history of Axis I or II Disorder (Normal Controls:NCs). For the rest, 210 (73.2%) had a current, and 266 (92.7%) hada life history of an Axis I Disorder. In addition, 239 (83.3%) had anAxis II Personality Disorder. Among this group of psychiatricsubjects about two-thirds met Research Criteria for IntermittentExplosive Disorder (IED-IR), a disorder of impulsive aggression(Coccaro, 2011). Accordingly, the psychiatric subjects were groupedas follows: 45 Axis I Disorder subjects, 49 Axis II Disorder subjects,193 IED-IR subjects.

2.4.2.2. Measures. In addition to completing the LHIB-Q20,subjects also completed self-report measures of impulsivity,aggression, neuroticism, and extraversion. Self-report impulsivitywas measured by the Barratt Impulsivity Scale (BIS-11; Patton et al.,1995) and by I7 Impulsivity (Eysenck, 1993). Aggression wasassessed by the Life History of Aggression (Coccaro et al., 1997).Neuroticism and extraversion were assessed by the full version ofthe EPQ-1 (Eysenck and Eysenck, 1975).

2.4.3. Results2.4.3.1. Administration time. Most subjects completed the LHIB-Q20 in less than 3 min. This was expected since the LHIB-SR-20has only 20 response items (i.e., 20 question items � 1 responseper item), as opposed to the 159 response items (i.e., 53 questionitems � 3 responses per item) in the original LHIB-Q53.

2.4.3.2. Internal reliability. As in Study II, the internal reliability ofthe LHIB-Q20 was very high (a ¼ .95); it did not differ as a functionof diagnostic groups (Range: .90 to .95). Test-retest data for theLHIB-Q20 was not collected in Study IV because this data hadalready been collected and analyzed in Study II.

2.4.3.3. Concurrent validity. As in Study II, LHIB-Q20 scores corre-latedwith BIS-11 Total Impulsivity scores (r¼ .65, n¼ 354, p< .001)and with I7 Impulsivity scores (r ¼ .59, n ¼ 358, p < .001); BIS-11and I7 scores were also highly correlated (r ¼ .70, n ¼ 335,p < .001). Multiple regression with LHIB-Q20 as the dependentvariable (R¼ .68, R2 ¼ .47, F[2332]¼ 145.46, p< .001), revealed thatthe unique contribution of BIS-11 to LHIB-Q20 scores was partr ¼ .34 and the unique contribution of I7 to LHIB-Q20 scores waspart r ¼ .19. Multiple regression of LHIB-Q20 scores with the threesubscales of the BIS-11 (R ¼ .70, R2 ¼ .49, F[4330] ¼ 78.57, p < .001)revealed unique contributions for Motor Impulsivity (part r ¼ .23,p< .001) and Attentional Impulsivity (part r ¼ .16, p< .001) but notfor Non-Planning Impulsivity (part r¼ .06, p> .12). As expected, theLHIB-Q20 separated the diagnostic groups (F[3, 375] ¼ 66.46,p < .001) with Axis II Disorder subjects having a greater history ofimpulsive behaviors than Normal Controls or Axis I Disordersubjects and IED-IR subjects having the greatest history of impul-sive behaviors compared with the other groups; Fig. 1.

2.4.3.4. Correlations with related constructs and divergent val-idity. As in Study II, LHIB-Q20 scores correlated highly with LHAaggression (r ¼ .66, p < .001) and with EPQ-1 Neuroticism (r ¼ .62,n ¼ 362, p < .001). Unlike Study III, EPQ-1 Extraversion was posi-tively, and significantly, correlated with LHIB-Q20 scores (r ¼ .34,n ¼ 362, p < .001). Multiple regression analysis (R ¼ .74, R2 ¼ .55,F[3353] ¼ 144.38, p < .001) revealed that LHA Aggression uniquelyaccounted (part r ¼ .38, r2 ¼ .14, n ¼ 356, p < .001) for twice asmuch of the overlapping variance with LHIB-Q20 scores as did EPQ-1 Neuroticism (part r¼ .26, r2 ¼ .07, n¼ 356, p< .001) and for morethan ten times the overlapping variance as did EPQ-1 Extraversion(part r ¼ .12, r2 ¼ .01, n ¼ 356, p ¼ .001).

2.5. Discussion of Study III

Study III examined the psychometric properties and perfor-mance of the LHIB-Q20 in a group of normal controls and psychi-atric subjects. The revised version of the LHIB-Q required less than

E.F. Coccaro, C.A. Schmidt-Kaplan / Journal of Psychiatric Research 46 (2012) 346e352 351

3 min to complete, a clear advantage over the original version.Again, the LHIB-Q20 is internally consistent. Evidence of itsconcurrent validity is supported by the strong association betweenthe LHIB-Q20 and both the BIS-11 and I7 impulsivity measures. Asexpected, the degree of shared variance with both measures wassubstantial. However, it also leaves at least 50% for unique variance(i.e, up to 58%, and 65%, for BIS11 and I7, respectively). Examiningthe unique contributions for both BIS-11 and I7 in the context ofa multiple regression analysis increases the degree of uniquevariance for the LHIB-Q20 to 66%e81%. Focusing on the BIS-11 andits sub-scores, BIS-11 Motor and Attentional impulsivity bothuniquely contributing to their shared variance with the LHIB-Q20.This suggests that Non-Planning Impulsivity, as defined by theBIS-11, is not manifested as actual impulsive behavior but simplyreflects the tendency to not think through one’s actions. Alterna-tively, it is possible that the variance explained by non-planningimpulsivity items fully overlap with that explained by motor andattentional impulsivity.

The LHIB-Q20 also demonstrates differences in scores by diag-nostic categories, with both Normal controls and Axis I Disordersubjects scoring similarly and those with Axis II Disorders scoringsubstantially higher. Several Axis II Disorders contain an element ofimpulsivity, thereby making it more likely that those with Axis IIDisorders should score more highly than those without thesedisorders. IED-IR subjects score the highest of all. This was antici-pated since impulsive behavior is reflected in the impulsiveaggressive acts of subjects with IED-IR.

The LHIB-Q20 also correlates significantly with measuredaggression as well as with neuroticism. However, the LHIB-Q20 isalso associated with extraversion. Much more of the variance isaccounted for by aggression and then neuroticism as compared toextraversion, reflecting the stronger association between impul-sivity and the former two constructs as compared with the latter.Given that the LHA includes impulsive aggressive behaviors andthat those who score high on neuroticism may have difficultiesdelaying gratification, it is reasonable to observe this relationship.Extraversion also includes an element of a preference for excite-ment, which may account for its smaller relationship with theLHIB-Q20.

3. Conclusion

The findings of these studies suggest there is significantevidence to support the validity of the self-report version of theLHIB. Internal consistency and test-retest reliability are excellentand more than acceptable. Additionally, the LHIB-Q correlatessignificantly with other self-reported measures of impulsivity, butin a way that adds unique information to the construct of impul-sivity.The LHIB-Q can also be reliably used with informants, addingsupport to the notion of validity and also increasing the utility ofthe measure. The LHIB-Q demonstrates significant differences, inthe anticipated direction, between subjects in a priori diagnosticcategories thought to have differing degrees of impulsivity, offeringadditional evidence of the validity of the LHIB-Q20. Finally theLHIB-Q20 can be completed quickly and efficiently, increasing theutility of the measure, especially in the case of large studies wheremany behavioral measures will be assessed.

The LHIB-Q20 can be used alone if one only wishes to have anassessment of an individual’s history of actual impulsive behavior.The LHIB-Q20 may also be used in combination with anotherpersonality-trait assessment of impulsivity, such as BIS-11 (or I7)Impulsivity, in which case both history of impulsive behavior andpersonality-trait impulsive tendencies are assessed simultaneously.Despite the strong correlation of LHIB-Q20 with BIS-11, in Study III,for example, 58% of the variance of a latent construct of trait

impulsivity is not shared by one or the other measure. Accordingly,both measures, together, should account for a substantial degree ofthis unshared variance and yield a more comprehensive assess-ment of trait impulsivity in human subjects. For example, in thecase of the relationship between impulsivity and aggression(i.e., LHA Aggression) in Study III, we found that addition of the BIS-11 to the model adds a statistically significant increase in explainedvariance (i.e., R2 from .432 to .449; F Change: [1346] ¼ 10.68,p < .001). While this increase in explained variance is small (4%),the addition in explained variance with other measures may begreater and should be explored.

Role of funding source

This work was supported by NIH Grant R01MH63262 (Dr. Coc-caro) which funded the questionnaire study of adult twin subjectsin Study II and by NIH Grants RO1MH60836 and RO1MH66984(Dr. Coccaro) which funded the work with the patient and controlsubjects in Study III.

Conflict of interestThere are no conflicts of interest regarding this work.

Acknowledgments

The authors thank the content experts queried in Study 1a,particularly: Ernest Barratt, Ph.D., Mitchell Berman, Ph.D., ScottBunce, Ph.D., Maurizio Fava, M.D., Peter Giancola, Ph.D., JefferyHalperin, Ph.D., Richard Kavoussi, M.D., Markus Kruesi, M.D., F.Gerry Moeller, M.D., and Christopher Reist, M.D.We also thank BingChen,M.S. for her assistance in datamanagement over the course ofthis study.

Appendix. Life History of Impulsive Behavior (LHIB-Q20)

How many times would you say you did the following thingsover the course of your adult life to date?

0 ¼ never happened.1 ¼ happened only “once”2 ¼ happened 2e3 times.3 ¼ happened 4e9 times.4 ¼ happened more than 10 times.5 ¼ happened too many times to count

1. Changed your plans at the last minute?2. Quickly lost your temper or quickly become angered by

someone?3. Made a quick decision to do something that could be physically

dangerous to yourself such as step into a fight or cross a busyroad without waiting for the light to change first?

4. Said what was on your mind without thinking it through first?5. Jumped at the first opportunity to do something without

thinking about the risks or problems that might arise fromyouractions?

6. Not finished a project or task because you got involved inanother one?

7. Made plans that didn’t work out because they weren’t thoughtthrough enough?

8. Jumped to a quick decision about how to handle a problem thatwas upsetting you?

9. Had difficulty keeping out other thoughts when trying to solvea problem?

10. Felt as if your thoughts were “racing” from one idea to another?11. Found that your thoughts were being ruled by your emotions?12. Done something without thinking because you were bored?

E.F. Coccaro, C.A. Schmidt-Kaplan / Journal of Psychiatric Research 46 (2012) 346e352352

13. “Lost control” of your emotions?14. Found yourself acting on a whim?15. Found yourself losing interest in a hobby, activity, or sport soon

after you had taken it up?16. Left an argument or discussion suddenly and before it was

over?17. Suddenly ended a friendship?18. Quit one job before you had another job to go to?19. Been surprised that your actions led to unpleasant

consequences?20. Become emotionally involved with someone immediately after

meeting him or her?

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