Invulnerability, Optimism Bias and Risk Behavior in Late Adolescence

Daniel K. Lapsley and Patrick L. Hill

University of Notre Dame, USA

Available at: www.nd.edu/~dlapsle1

Background

Two explanations of risk behavior are prominent. One explanation suggests that risk appraisal is compromised by a pervasive optimism bias whereby individuals assume more favorable outcomes for the self than for others. This approach follows the biases-and-heuristics paradigm in its assumption that risk judgment is best modeled by asking individuals to estimate the chances, likelihood or probability that negative events would happen to the self (and to others). As intuitive statisticians individuals tend to be optimistic about their chances of getting cancer if they smoke or of contracting an STD if they are sexually active. As Weinstein (1980, p. 806) put it, “people tend to think they are invulnerable.”

A second explanation links risk behavior to felt invulnerability that has a presumptive developmental source; or else treats invulnerability not as a cognitive error in decision-making but as an attitudinal variable and as a dimension of individual differences (Lapsley, 2003).

To date the invulnerability and optimism bias approaches to risk judgment have not been examined conjointly.

Moreover, although optimism bias and invulnerability are said to underwrite “risky decision-making”, few studies have attempted to empirically document this relationship

The purpose of this study was two-fold. First, to test the relative contribution of optimism bias and invulnerability to risk behavior. Second, to determine the extent to which invulnerability and optimism bias are associated with risky decision-making.

European Adolescent Research Association

Turin, May 2008

Conclusions

Although invulnerability and optimism bias were moderately correlated, invulnerability was more strongly and pervasively correlated with risk behavior (delinquent behavior and life time drug use) than was optimism bias; and was the sole predictor of risk behavior (and drug use) in regression analysis.

In addition, the relationship of invulnerability and optimism bias to risk behavior does not seem to be underwritten by “risky decision-making” as measured by the Iowa Gambling Task. The IGT was not related to these constructs, nor was it correlated with risk behavior.

Invulnerability and optimism bias appear to be overlapping but independent constructs that should not be conflated in analysis of risk behavior; nor confused with “risky decision-making” in the sense measured by the Iowa Gambling Task.

Method

Participants: 114 (78 males) late adolescent (Mage = 19.57, SD = 1.29) university students.

Instruments:

Iowa Gambling Task. The IGT is a measure of “risky decision-making” that requires participants to select among 4 decks of cards that reflect varying degrees of risk. In this study the IGT was scored to reflect the percent of “safe” (non-risky) choices over 100 trials (so that high scores indicate less risky decision-making).

Adolescent Invulnerability Scale. The AIS is a 20-item scale that requires participants to indicate their level of agreement with statements that reflect an inability to be injured, harmed or High scores indicate greater felt invulnerability. The reliability was α = .83

Optimism Bias. Participants judged the likelihood of negative outcomes if they engaged in each of 18 behaviors. Risk assessment was both comparative (“Compared to other Notre Dame students) and conditional (“…if you did X”). The rating scale ranged from -3 (Much below average) to +3 (Much above average). Negative scores indicate optimism bias. The reliability was α = 74.

Delinquent Risk Behavior. Using a scale designed by Rowe (1985), participants rated the extent to which they engaged in 20 risk behaviors, including fast driving, stealing, fighting, and vandalism, along a 4-step continuum (no/never, one time/rarely, several times, very often). The reliability was α = 83.

Lifetime Drug Use Participants indicated how many times in their life they have used alcohol, tobacco and various drugs (marijuana, hallucinogens, cocaine, meth) on scale ranging from “never” to “40 or more” times. The reliability was α = 63.

Coefficientsa

33.039 6.605 5.002 .000

-3.784 1.450 -.254 -2.609 .011

.182 .084 .217 2.174 .032

-.088 .066 -.126 -1.335 .185

-4.974 4.007 -.115 -1.241 .217

(Constant)

Gender

Invulnerability

Optimism Bias

Iowa Gambling Task

Model1

B Std. Error

UnstandardizedCoefficients

Beta

StandardizedCoefficients

t Sig.

Dependent Variable: Delinquent Risk Behaviora.

Optimism Bias Ratings(negative scores indicate more optimism bias)

Items Mean Std. Dev.

being injured in a tornado if one struck near yougetting caught if you cheat on a testgetting an STD if having unprotected sexgetting caught for vandalismgetting arrested for using illegal substancesgetting caught illegally downloading materialsgetting caught for shopliftingbecoming an alcoholic if drink regularlyhaving cavities if don’t visit dentist regularlybeing mugged in a dangerous neighborhoodfailing a test if don’t studygetting an “A” if you study for examgetting an interview if apply for a jobbeing injured if involved in a fightbeing rejected if ask someone for a dategetting divorced if you marrygetting in an accident if drive over speed limitgetting lung cancer if you smoke regularly

-.61-.52-.25-.65-.71-.38-.73-.67-.07-.24.08-.51-.87-.14-.55

-1.19-.54.15

1.161.271.181.391.681.371.491.381.191.221.471.261.121.291.211.271.071.07

Correlations

1 -.301** .087 .315** .305**

.001 .384 .001 .001

112 112 102 111 111

-.301** 1 .106 -.213* .004

.001 .283 .024 .971

112 114 104 113 113

.087 .106 1 -.091 .005

.384 .283 .357 .963

102 104 104 104 103

.315** -.213* -.091 1 .576**

.001 .024 .357 .000

111 113 104 113 112

.305** .004 .005 .576** 1

.001 .971 .963 .000

111 113 103 112 113

Pearson Correlation

Sig. (2-tailed)

N

Pearson Correlation

Sig. (2-tailed)

N

Pearson Correlation

Sig. (2-tailed)

N

Pearson Correlation

Sig. (2-tailed)

N

Pearson Correlation

Sig. (2-tailed)

N

Invulnerability

Optimism Bias

Iowa Gambling Task

Delinquent RiskBehavior

LifeTime Drug Use

Invulnerability Optimism

BiasIowa Gambling

Task

DelinquentRisk

BehaviorLifeTimeDrug Use

Correlation is significant at the 0.01 level (2-tailed).**.

Correlation is significant at the 0.05 level (2-tailed).*.