Personality and Impulsivity

Abstract

Previous research has done little to assess the disparity or overlap of constructs measured by self-report compared to lab-based tests. This study aimed to look at the approaches to measuring the multidimensional construct of impulsivity and review the discrepancies between self-report and lab-based testing. Furthermore it aimed to determine which traits are assessed by different measures of impulsivity and discuss which approach is better in the measurement of impulsivity. The review concluded that self-report testing primarily showed long-term traits of impulsivity and had high validity. Alternatively, lab-based testing showed state levels of impulsivity and had greater potential for predicting impulsive behaviour. In conclusion, the combination of both self-report and lab-based testing gives the most comprehensive measurement of impulsivity including both trait and state aspects.

Impulsivity represents one of the major multifaceted constructs integral to psychopathological understanding. Cyders and Coskunpinar (2012) state that impulsivity is composed of ten discrete constructs such as positive and negative urgency as well as resistance to proactive or distractor interference to name a few. Therefore due to its complex nature, impulsivity can be measured through multiple means such as self-report or lab-based testing. This leaves an individual open to great discrepancies in impulsivity scores depending on the measure used and whether it is measuring state or trait impulsivity (Cyders & Coskunpinar, 2011). Therefore it has become vitally important to understand the construct overlap of different types of tests in different scenarios. Although previous research has found that self-report and lab-based tasks of impulsivity measure constructs which load on separate factors, little has been explored to determine which testing has greater validity and usefulness in the measurement of impulsivity (Morgan, Gray, & Snowden, 2011). This report aims to critically examine some of the most common self-report tasks and lab-based measures of impulsivity and discuss the advantages and disadvantages of each method. Furthermore, it aims to compare the two types of testing and discuss which type of testing is appropriate for different situations. This can be determined by examining to what degree the constructs measured in self-report versus lab-based testing are overlapping or distinct. The implications of these findings will be used to guide future impulsivity testing in research and clinical settings.

Self-report tests have been used in the domain of psychology and particularly in the area of personality as a relatively inexpensive and fast method of obtaining information from a large group of people (Verdejo-Garcia, Lozano, Moya, Alcazar & Perez-Garcia, 2010). One of the greatest advantages is that self-report can provide a large amount of insight into individual differences in feelings, thoughts and behaviour given the participant is aware and capable of self-reflection. Hence, this testing is inappropriate for people with significant learning or psychological disabilities. Self-report studies benefit from high face validity due to the clarity and relevance of the types of questions asked to participants. However, interestingly face validity has also been one of the major weaknesses for self-report due to participants’ tendency to answer in a dishonest or manipulative manner (Cyders & Coskunpinar, 2011). Although some self-report tasks have tried to conquer this with inbuilt validity scales such as the MMPI-2 that includes a lie scale and a faking good or bad scale amongst others. Finally, self-report measures are recognised as measuring general traits over time and are therefore limited in their ability to measure state impulsivity or predict behaviour in a given situation.

One commonly used self-report task is the UPPS-P impulsive behaviour scale. This requires participants to rate 59 items on a four-point Likert scale measuring positive and negative urgency, lack of perseverance, lack of deliberation and sensation seeking as dispositions of impulsivity. Verdejo-Garcia et al. (2010) showed that as well as being adequately reliable, the five dimensions of UPPS-P also measured different aspects of impulsivity, contributing to construct validity. Another predominant self-report measure of impulsivity is the Barratt impulsivity scale (BIS-11) that measures impulsivity through three constructs: motor, attentional and non-planning using a 30-item Likert-scale questionnaire. The BIS-11 produces adequate internal consistency and is useful in differentiating between non-pathological and pathological groups such as those with high aggression or ADHD (Ireland & Archer, 2008). This high correlation with impulsive-related pathological groups indicates a high level of construct validity in the BIS-11. The BIS-11 amongst other self-report tasks also shows very high levels of test-retest validity compared to behavioral tasks (Fossati, Di Ceglie, Acquarini, & Barrat, 2001). However in the research surrounding self-report measures of impulsivity, findings have shown a lot of support for the five-dimensional model of impulsivity, two of which are emotional, two of which are based on deficits in conscientiousness and one in sensation seeking. If this is taken as a reliable and valid measure of impulsivity then it is important to correlate these constructs with lab-based tests of impulsivity. Both of these tests aim to measure traits that are reflected in long-term behavior and responses but have little ability to predict impulsive behavior or responses given different states of an individual.

Behavioural tests measuring impulsivity are important in providing information about the underlying traits and processes that are not measured in self-report tasks. Due to the low face validity, behavioural tasks are considered to be more robust against deception and false reporting tendencies (Meda, Stevens, Potenza, Pittman, Gueorguieva, Andrews, Thomas, Muska, Hylton, & Pearlson, 2009). They are also a necessary alternative to self-report for those who have low insight or are affected by learning or psychological disability. Lab-based tests provide a greater prediction of what an individual would actually do in a situation or in response to specific stimuli and can focus on the underlying processes occurring. However, conversely to self-report tasks, lab-based tests tend to measure states of impulsivity and are limited in their ability to assess longer lasting traits of impulsivity. Furthermore, due to the disparity between self-report and behavioural tasks it is hard to discern whether the response in a lab is correlated with individual traits.