不同类型罪犯在爱荷华赌博任务中的决策功能缺陷

Different Types of Criminals’ Decision-making Defects in the Iowa Gambling Task

采用爱荷华赌博任务(Behcara等人1994年版本)测量了8类共222名在监男性罪犯以及32名普通男性的决策功能,并运用前景效用学习模型分析了不同类型罪犯在情感决策中的心理功能缺陷。罪犯组选择牌1的比例与控制组没有显著差异,选择牌2的比例显著高于控制组,选择牌3和牌4的比例显著低于控制组。暴力犯和涉黑犯对收益和损失都不敏感,对过去的预期效用折扣很快;吸毒犯(已戒除)、涉毒犯、盗窃犯和抢劫犯对奖赏加工正常,对惩罚不敏感;经济犯选择一致性最低;性罪犯选择一致性最高。结果表明不同类型罪犯在爱荷华赌博任务中都具有决策功能缺陷,但他们的决策功能缺陷由不同的心理功能缺陷所致。

Affective decision making is an individual ability to make choice under uncertainty. Criminal behavior is a result of criminals＇ decision-making under uncertainty. Criminals are to be fettered and thrown into prison because they have made wrong decisions. Are there any defects of different types of criminals＇ decision-making function？ If there are, what caused their defects？ And are these reasons different or the same？ The Iowa Gambling Task （IGT） which developed by Bechara et al. （1994） has been widely used to evaluate decision-making ability under uncertainty. In this study, 222 male criminals and 32 controlled normal males were recruited. All of them were asked to fill out a demographical form and then complete IGT. A 10 （block）×9 （participant type： 8 types of criminal group and 1 control group） experimental design was adopted. The independent variables were patricipant type and block, dependent variable were the proportion of advantage decks [（deck3＋deck4）/100] and each deck. The Prospect Utility Learning model （PUL） （Ahn et al., 2008） was applied to analysis participants＇ choices behavior. PUL model contained four parameters： loss aversion （2）, shape of function （α）, learning update rate （A）, and choice consistency （c）. A repeated ANOVA was applied to the data analysis. （1） Along with time passing, control group chose more from advantage deck 3 and 4, but 8 types of criminals preferred disadvantage deck 2. There was no significant difference in disadvantage deck 1 between criminals and control group： （2） Comparing to the control group, violent offenders and mafia-like criminals＇ loss aversion parameter and shape of function parameter were significant lower, which indicated that they were not sensitive to reward and punishment. Their learning update rate was higher than control and other types of criminals which indicated that they were fast discount the utility of past events. And their choice consistency was significant higher than other types of participant indicated that they did not form right utility of each deck. Drug abstainers, drug criminal, thief and robbery were lower in the loss aversion parameter, which indicated that they were insensitive to punishment; there higher choice consistency indicated that they did not form right utility of each deck. Sex offender＇s choice consistency parameter was higher than control, but their loss aversion, shape of function, and learning update rate parameters were normal. So, their high choice consistency may indicate that their behavioral reversal function were defected. Economic criminal＇s choice consistency was very low may indicated that they were more cautious than other types of criminal. In conclusion, the present research suggested that different types of criminal have decision-making functional deficits, and the reasons caused these deficits were different.