Relevant Degree Programs
Great Supervisor Week Mentions
Last year, on Supervisor Appreciation Day, we dedicated our waiting area to @LukeClark01. This year, we re-dedicated it. We're so proud, we made mugs. Every grad student in the lab bought one. #GreatSupervisor #UBC
Well @LukeClark01, another Supervisor Appreciation Week is upon us. Without being overly cloying, here are 3 things I really like about working for you. #greatsupervisor #UBC
1. You put a huge amount of work into editing and improving our writing. Sorry I took 5 years to learn the difference between 'While' and 'Although.'
2. At least 3 or 4 times a year, you keep me from doing (or tweeting!) something that would seriously impact my career.
3. Your (almost encyclopedic) knowledge of papers (and authors... and journals...) is so impressive that I sometimes try to figure out exactly how you do it. Thanks, Luke!
A #GreatSupervisor deserves thanks, but an awesome supervisor deserves pranks. @LukeClark01, the lab thanks you for your effort. #ubc
Graduate Student Supervision
Master's Student Supervision (2010 - 2018)
Gambling decisions are inherently risky decisions involving wins and losses. The severity of gambling problems varies with the persistence of betting despite mounting losses. ‘Prospect Theory’, a descriptive model of risky decision-making from the field of behavioural economics, describes an influential phenomenon called Loss Aversion: the natural tendency for “losses to loom larger than gains” when people evaluate risky choices (Kahneman and Tversky, 1992). It is an intuitive prediction that people with the more severe gambling problem will display systematic alterations in their loss aversion. Experiment 1 reviewed two widely-used loss aversion tasks (the ‘matrix’ and ‘staircase’ methods) in the past studies, which also have varied in whether trial-by-trial outcome feedback was presented within each task. Hence, Experiment 1 was a methodological study. It aimed to evaluate whether the presentation of outcome feedback influences loss aversion scores with student samples, as a precursor for Experiment 2 using this procedure in regular gamblers. Experiment 2 recruited non-problem gamblers with varying levels of sub-clinical gambling problems. With the established task, it studied the relationships between the severity of gambling problems and risk preferences including risk attitudes across the gain and loss domains, loss aversion, and probability distortions. In Experiment 1, the outcome feedback did not show significant influence on the level of loss aversion. In Experiment 2, the findings indicated that the risk attitudes in the gain domain were the only Prospect Theory-based variable that correlated with the severity of gambling problems; participants with more severe problems tended to be more risk-seeking in the gain domain, and in the loss domain, all participants displayed ambivalent choices between risk-seeking and risk-averse. Moreover, the level of loss aversion and the magnitudes of probability distortions for potential gains and losses did not correlate with the severity of gambling problems.
Testosterone can be seen to modulate cognition and behaviour in many ways. One likely effect is to promote risky decision-making. According to a phenomenon termed the “winner-loser effect,” testosterone has also been observed to fluctuate in response to winning or losing competitions with others, with wins causing increases and losses causing decreases. Surprisingly, few studies have investigated the effects of gambling on testosterone levels, or whether individual differences in testosterone are related to risky gambling strategies. More specifically, the winner-loser effect may extend to slot machine gambling as a solitary gambling activity if players tend to ‘anthropomorphize’ slot machines, i.e. to treat the machine as a human agent with intentions and feelings. This study used a quasi-experimental design to measure testosterone fluctuations in response to winning and losing during a period of authentic slot machine gambling. Cortisol and anthropomorphism were investigated as potential moderators of a winner-loser effect on testosterone. Male participants (n = 120) provided saliva samples before and after a period of gambling on an authentic slot machine. Participants also provided measures of real-world gambling involvement, subjective experiences during slot machine play, and anthropomorphic tendencies. Contrary to predictions, winning and losing were not significantly associated with divergent effects on testosterone, even after considering cortisol levels and anthropomorphization of the slot machine. An exploratory analysis supported a link between positive affect (higher in winners) and decreases in testosterone, which suggested that the winner-loser effect may be reversed in slot machine gambling. In addition, baseline testosterone predicted a slower rate of gambling. The results of this study add to a growing literature on the boundary conditions of the winner-loser effect, which inform future examinations of the role of testosterone in gambling behaviour.