Illusory correlation, group size and memory

Two studies were conducted to test the predictions of a multi-component model of distinctiveness-based illusory correlation (IC) regarding the use of episodic and evaluative information in the production of the phenomenon. Extending on the standard paradigm, participants were presented with 4 groups decreasing in size, but all exhibiting the same ratio of positive to negative behaviours. Study 1 (N = 75) specifically tested the role of group size and distinctiveness, by including a zero-frequency cell in the design. Consistent with predictions drawn from the proposed model, with decreasing group size, the magnitude of the IC effect showed a linear in- crease in judgments thought to be based on evaluative information. In Study 2 (N = 43), a number of changes were introduced to a group assignment task (double presentation, inclusion of decoys) that allowed a more rig- orous test of the predicted item-specific memory effects. In addition, a new multilevel, mixed logistic regression approach to signal-detection type analysis was used, providing a more flexible and reliable analysis than previ- ously. Again, with decreasing group size, IC effects showed the predicted monotonic increase on the measures (group assignment frequencies, likability ratings) thought to be dependent on evaluative information. At the same time, measures thought to be based on episodic information (free recall and group assignment accuracy) partly revealed the predicted enhanced episodic memory for smaller groups and negative items, while also supporting a distinctiveness-based approach. Additional analysis revealed that the pattern of results for judg- ments though to be based on evaluative information was independent of interpersonal variation in behavioral memory, as predicted by the multi-component model, and in contrast to predictions of the competing models. The results are discussed in terms of the implications of the findings for the proposed mechanisms of illusory correlation

Misinformation, Misrepresentation, and Misuse of Human Behavioral Genetics Research

Kaplan discusses the limitations of human behavioral genetics studies, highlighting the research limitations inherent in studying humans and the narrow policy and legal applicability of results arising from behavioral genetics studies

Illusory correlation: interplay of evaluative group impression and item-specific episodic memory

Illusory Correlation (IC) is the perception that two events are associated with each other, when in reality they are not. The current study tested predictions of the Multiple Component Model (MCM) regarding the role different types of information (i.e., evaluative and item-specific information) play in producing the IC effect. The current study extended previous experiments on IC, particularly that by Van Rooy, Vanhoomissen and Van Overwalle (2013), in using two independent trait dimensions (i.e., Common Trait and Rare Trait), rather than the traditionally used one evaluative dimension (i.e., frequent, desirable vs. infrequent, undesirable behaviours). The MCM predicted that, judgements based on evaluative information, would result in an association between the majority group and the common trait (Majority-Common Trait), whereas the minority group would be associated with the rare trait (Minority-Rare Trait). For judgements based on item-specific ! episodic memory, the MCM predicted enhanced memory amongst participants for Minority-Rare Trait statements. Partial support was found for both predictions: Participants did develop a Majority-Common Trait association, but no particular association was formed with the minority group. Additionally, participants did show enhanced memory for Minority-Rare Trait statements. However, they also showed unexpected enhanced memory for Majority-Rare Trait statements. Together, the current results further elucidate the interplay of evaluative and item-specific information when reporting judgments on a majority and minority group respectively. The finding of a Majority-Rare Trait association however, implies the need for further studies to examine the exact nature (i.e., evaluative or episodic) of this association and its implications in causing IC

Predicting private and public helping behaviour by implicit attitudes and the motivation to control prejudiced reactions

The role of individual differences in implicit attitudes toward homosexuals and motivation to control prejudiced reactions (MCPR) in predicting private and public helping behaviour was investigated. After assessing the predictor variables, 69 male students were informed about a campaign of a local gay organization. They were provided with an opportunity to donate money and sign a petition in the presence (public setting) or absence (private setting) of the experimenter. As expected, more helping behaviour was shown in the public than in the private setting. But while the explicit cognitive attitude accounted for helping behaviour in both settings, an implicit attitude x MCPR interaction accounted for additional variability of helping in the public setting only. Three different mediating processes are discussed as possible causes of the observed effects

Birds of a Feather Sit Together: Physical Similarity Predicts Seating Choice

The relationship between physical similarity and seating preference was examined using two observational studies and one laboratory study. Using Campbell et al.’s (1966) seating adjacency formula, Study 1 found significant aggregation by glasses-wearing status and sex when observing seating patterns in a library computer lab. That is, men sat beside other men, glasses-wearers by other glasses wearers, and so on. Study 2 broadened this methodology by examining a wider variety of physical traits in university classrooms; specifically, race, sex, glasses-wearing, hair length and hair colour. Broadly speaking, multivariate tests revealed an overall tendency for people to sit beside physically similar others more frequently than expected by chance alone. These results remained significant even when controlling for sex, race or prior acquaintanceship. Study 3 conceptually replicated these results in a laboratory setting. Photos of participants were coded for physical similarity to a confederate and attractiveness by independent coders. The more physically similar participants were to a confederate, the closer they sat. This finding remained significant even when controlling for sex, race and attractiveness similarity. Other nonverbal measures were also examined as potential dependant variables; however, only speech disfluencies emerged as a significant correlate with physical similarity. As physical similarity increased, the number of speech disfluencies uttered by the participant during a short interaction also increased. The potential moderating role of implicit self esteem and body esteem on the physical similarity/seating distance relationship was also examined. However, these results were nonsignificant. Finally, as perceived similarity to the confederate increased, so did positive ratings of the confederate using Likert scales; however, perceived similarity did not predict any nonverbal measures. The current research rules out simple matching on sex, race or attractiveness as potential explanations for this finding. An evolutionary kinrecognition mechanism is discussed as a potential mechanism behind these findings, drawing on Debruine’s (2004a) work. However, much work is left to be done to more concretely determine the driving force behind this relationship