The materials and procedure used were the same as described for study two. Participants read the information sheet and instructions, after which they signed the consent form and returned it to the experimenter. The purpose of this study was to investigate the relationship between reward sensitivity, male participants’ age and risky Deck B choices. Therefore only the sensitivity to reward subscale of the SPSRQ was administered. They then completed 100 trials of the IGT on a laptop in their own time. Once the trials were completed, participants received a debrief form, were given the opportunity to ask any questions about the study, and were thanked for their time. All paid participants were awarded £4 for their time.
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3.3.2 Results
The mean scores for sensitivity to reward were calculated, rank ordered and then a median split divided the scores in half. The two halves were labelled as high and low [sensitivity to reward].
The high sensitivity to reward group consisted of scores over 13.1, and the low sensitivity to reward group of scores less than 13.1.
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Table 3.2 provides descriptive information on participants’ mean Deck B choices on the IGT, separated by age group and organised by sensitivity to reward (HSR/ LSR). As can be seen, highly sensitive to reward young males chose many more cards from Deck B than low sensitive to reward young males. Conversely, low sensitive to reward older males chose more cards from Deck B than highly sensitive to reward older males.
Table 3.2. Descriptive statistics for participants’ Deck B choices, organised by their sensitivity to reward scores. males. High reward sensitive young males chose more cards from risky Deck B than low reward sensitive young males or any older males. A 2x2 ANOVA revealed a significant interaction between age and reward sensitivity on the number of Deck B cards chosen, F(1, 75) = 7.3, p<
.01; and a simple main effect of age F(1, 75) = 6.3, p< .05 but not reward sensitivity F(1, 75) = .64, p> .05. The relationship between risky behaviour and reward sensitivity for young and older males is shown in Figure 3.5. It can be seen that males of all ages who were low in reward sensitivity chose a similar number of Deck B cards, but high reward sensitive young males chose more cards from this deck than high reward sensitive older males. One-way ANOVAs
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confirmed that whilst there was no significant difference in number of Deck B choices between the two age groups for those low in reward sensitivity F(1,40) = .02, p> .05, this difference was significant for those high in reward sensitivity F(1, 35) = 13.3, p< .01. High reward sensitive young males chose significantly more risky Deck B cards than high reward sensitive older males.
Figure 3.5. Total number of cards chosen from Deck B over 100 trials of the IGT, by high versus low sensitivity to reward young male and older male participants.
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3.4 Discussion
In this study choices from Deck’s B and C on the IGT were examined in relation to measures of reward sensitivity and punishment sensitivity. We were interested in this because it was thought that heightened reward sensitivity might be an underlying factor motivating young males to engage in risk-taking behaviour. It was hypothesized that high reward sensitivity would relate to more selections from Deck B, particularly for young males; and high punishment sensitivity would relate to less selections from Deck C throughout the duration of the task. It was found that greater Deck B selections were made only by reward sensitive young males, and not by reward sensitive females or older males, suggesting that higher levels of BAS are associated with riskier decisions on the IGT, for young males at least. High reward sensitive young males’
preference for Deck B increased as the task progressed, suggesting that their choice for this deck continued even after learning of the associated outcomes. This effect of reward sensitivity was unique to young males, with high reward sensitive older males making fewer risky Deck B selections by comparison. Fewer Deck C selections were not found to be related to higher scores of punishment sensitivity. These findings suggest that the relationship between reward sensitivity and risky behaviour may be what differentiates young males and underpins their risky driving.
The results give some insight into what may underpin young males’ aptitude for risky behaviour; and provides evidence to direct the design of future young driver interventions. As seen in chapter two current road safety campaigns tend to be punishment-oriented and focus on the potential negative consequences of risky driving. However as has been shown here, some young males make risky choices that reflect a particular sensitivity to reward rather than punishment. If some young males are motivated by reward rather than punishment, this might explain why males and females responded differently to the intervention in chapter two. In order to effectively target young males in the future, a different approach might benefit from utilising the knowledge that reward sensitivity underpins risky behaviour for the riskiest young males.
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The IGT was developed as a tool to study decision-making deficits in patients with vmPFC lesions. The validity of the IGT as a tool in clinical diagnosis has been challenged, with studies finding variation in the total number of cards selected from each deck by healthy participants (e.g. Caroselli et al, 2006). The findings from this study provide further support for the notion that some healthy individuals may not always make decisions based on long-term outcomes (Steingroever et al, 2013). The healthy young males in this study who were more sensitive to reward, tended to choose more cards from Deck B throughout the task. This suggests that they based their deck selections on high frequency gains and lower frequency of loss (even though when they did occur these losses were of a higher magnitude). Thus they preferred Deck B because they considered high magnitude immediate gain to outweigh the risk of a longer-term high magnitude loss.
Lin et al. (2007) suggested that individuals may do this because Deck B assures participants that they are more likely to win, and with a bigger amount. For these people, a negative long term outcome does not mean they will choose to avoid it, indicating that they are not even considering the long term negative consequences. Similarly, Rivalan et al.’s (2009) rat version of the IGT revealed that some rats systematically chose disadvantageously, regardless of the difficulty of the task. The authors suggested that their poor decision making did not occur through failure to learn how to make an advantageous decision, but rather through a hypersensitivity to reward and higher risk taking. The findings from the present study support this notion, as shown through the young reward sensitive males demonstrating a clear and consistent preference for Deck B throughout the course of the task. Whilst young females demonstrated a learning curve early on in the task, presumably realising the high risk associated with Deck B and thus selecting fewer cards from it, the reward sensitive young males continued to choose more cards from this deck throughout the 100 trials.
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The findings are in line with other research evidence related to decision making and reward sensitivity. For example Penolazzi et al. (2012) found that high reward sensitive individuals were more likely to underestimate loss when high gains could be achieved; and Buelow and Suhr (2013) found that individuals chose more cards from Deck B in the IGT when they also scored high on BAS-Drive, the continued desire to pursue a course of action for an end goal.
The results also add to the body of literature relating to reward sensitivity and risky health-related behaviours. Previously, greater sensitivity to reward has been found to relate to increased substance use (Genovese & Wallace, 2007); binge drinking and dysfunctional eating amongst young women (Loxton & Dawe, 2001). These studies have found reward sensitivity to be related to various risky health behaviours, and the findings from the present study suggest that for young males, reward sensitivity may underpin risky decision making.
Research conducted into the concept of a ‘teenage brain’ provides some explanation as to why the young reward sensitive males in this study may have based their decisions on immediate gratification rather than long-term outcomes. Siegel (2014) identified several changes that occur in the brain as an individual develops through adolescence and up to their mid-twenties. One of these changes is known as novelty-seeking, in which adolescents develop an increasing desire to seek out new and exciting experiences. Siegel (2014) suggested that novelty-seeking emerges from an increased desire for rewards in the circuits of the adolescent brain, motivating them to want to experience exciting, but often dangerous, events. Whilst this change does enable adolescents to have the courage to try new experiences, this is also accompanied by a strong desire to take risks. In this way, adolescents may engage in more risk-taking behaviours because the prospect of thrills is overemphasized and consideration of risks is minimised. Young males are known to be great sensation-seekers than females (Turner & McClure, 2003) and there is also evidence to suggest that male adolescents engage in some forms of real-world risk-taking more frequently than females (Harris, Jenkins & Glaser, 2006). Therefore taken together these findings lend further support to the idea that young males may be especially likely to engage in risk-taking behaviour over and above their female peers.
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The concept of the ‘teenage brain’ combined with the findings from this study adds further support to the idea that heightened reward sensitivity may underpin the risky driving behaviour of young males, showing how young males may be more likely to behave recklessly in order to satisfy their desire for reward. Previous research has found that heightened reward sensitivity is related to more self-reported errors, attention lapses and aggressive driving violations amongst young drivers (Constantinou et al, 2011). However the relationship between reward sensitivity, risky decision making and gender has not yet been investigated. By doing so here it has been shown that it is specifically the young male risk takers that make decisions based on immediate gratification and acceptance of risk, and do not consider the more advantageous long term outcomes. Young females and older males on the other hand are presumably more adept at considering the consequences and are thus less likely to be negatively affected by their desire for reward.
It should be noted that this was an exploratory study, considering the potential relationship between reward sensitivity and risky decision making. The IGT does not test decision making in the driving context and so it cannot necessarily be implied that reward sensitive young males will inevitably make risky decisions when driving just because they chose a certain deck in a computer game. However the relationship found here regarding young males’ reward sensitivity and their risky behaviour may also explain their heightened risk whilst on the road. So in order to provide further clarification about the role of reward sensitivity in young drivers’ risky driving behaviour study three considers this further, making use of a measurement tool relevant to the driving environment.
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