Sample size in psychological research over the past 30 years

The American Psychological Association (APA) Task Force on Statistical Inference was formed in 1996 in response to a growing body of research demonstrating methodological issues that threatened the credibility of psychological research, and made recommendations to address them. One issue was the small, even dramatically inadequate, size of samples used in studies published by leading journals. The present study assessed the progress made since the Task Force's final report in 1999. Sample sizes reported in four leading APA journals in 1955, 1977, 1995, and 2006 were compared using nonparametric statistics, while data from the last two waves were fit to a hierarchical generalized linear growth model for more in-depth analysis. Overall, results indicate that the recommendations for increasing sample sizes have not been integrated in core psychological research, although results slightly vary by field. This and other implications are discussed in the context of current methodological critique and practice.     

Signaling when (and when not) to be cautious and self-protective: impulsive and reflective trust in close relationships

A dual process model is proposed to explain how automatic evaluative associations to the partner (i.e., impulsive trust) and deliberative expectations of partner caring (i.e., reflective trust) interact to govern self-protection in romantic relationships. Experimental and correlational studies of dating and marital relationships supported the model. Subliminally conditioning more positive evaluative associations to the partner increased confidence in the partner's caring, suggesting that trust has an impulsive basis. Being high on impulsive trust (i.e., more positive evaluative associations to the partner on the Implicit Association Test; Zayas & Shoda, 2005) also reduced the automatic inclination to distance in response to doubts about the partner's trustworthiness. It similarly reduced self-protective behavioral reactions to these reflective trust concerns. The studies further revealed that the effects of impulsive trust depend on working memory capacity: Being high on impulsive trust inoculated against reflective trust concerns for people low on working memory capacity.     

Facial reactions reveal that slim is good but fat is not bad: Implicit and explicit measures of body‐size bias

Facial electromyography (EMG) was used to gauge emotional responding towards images of slim and overweight individuals, and findings were compared with data from a series of alternative measures including two implicit attitudinal procedures, the Implicit Relational Assessment Procedure (IRAP) and the Implicit Association Test (IAT), and explicit measures of anti‐fat prejudice and discriminatory behavior. Images of slim individuals elicited EMG responses consistent with more positive affect. Data from both the IRAP and IAT indicated higher levels of bias than were revealed on the explicit measures, and the IRAP also corroborated the EMG pattern by indicating responses consistent with pro‐slim rather than anti‐fat bias. The IRAP was moderately correlated with both EMG and the IAT and was the only measure to predict behavioral intentions. Copyright © 2011 John Wiley & Sons, Ltd.     

Common spatial organization of number and emotional expression: a mental magnitude line

Converging behavioral and neural evidence suggests that numerical representations are mentally organized in left-to-right orientation. Here we show that this format of spatial organization extends to emotional expression. In Experiment 1, right-side responses became increasingly faster as number (represented by Arabic numerals) or happiness (depicted in facial stimuli) increased, for judgments completely unrelated to magnitude. Additional experiments suggest that magnitude (i.e., more/less relations), not valence (i.e., positive/negative), underlies left-to-right orientation of emotional expression (Experiment 2), and that this orientation accommodates to the context-relevant emotion (e.g., happier faces are more rightward when judged on happiness, but more leftward when judged on angriness; Experiment 3). These findings show that people automatically extract magnitude from a variety of stimuli, representing such information in common left-to-right format, perhaps reflecting a mental magnitude line. We suggest that number is but one dimension in a hyper-general representational system uniting disparate dimensions of magnitude and likely subserved by common neural mechanisms in posterior parietal cortex.     

Mood stability versus mood instability in bipolar disorder: a possible role for emotional mental imagery

A cognitive model of bipolar disorder suggests that mental imagery acts as an emotional amplifier of mood and may be heightened in bipolar disorder. First, we tested whether patients with bipolar disorder would score higher on mental imagery measures than a matched healthy control group. Second, we examined differences in imagery between patients divided into groups according to their level of mood stability. Mood ratings over approximately 6-months, made using a mobile phone messaging system, were used to divide patients into stable or unstable groups. Clinician decisions of mood stability were corroborated with statistical analysis. Results showed (I) compared to healthy controls, patients with bipolar disorder had significantly higher scores for general mental imagery use, more vivid imagery of future events, higher levels of intrusive prospective imagery, and more extreme imagery-based interpretation bias; (II) compared to patients with stable mood, patients with unstable mood had higher levels of intrusive prospective imagery, and this correlated highly with their current levels of anxiety and depression. The findings were consistent with predictions. Further investigation of imagery in bipolar disorder appears warranted as it may highlight processes that contribute to mood instability with relevance for cognitive behaviour therapy.     

Fishing for happiness: the effects of generating positive imagery on mood and behaviour

Experimental evidence using picture-word cues has shown that generating mental imagery has a causal impact on emotion, at least for images prompted by negative or benign stimuli. It remains unclear whether this finding extends to overtly positive stimuli and whether generating positive imagery can increase positive affect in people with dysphoria. Dysphoric participants were assigned to one of three conditions, and given instructions to generate mental images in response to picture-word cues which were either positive, negative or mixed (control) in valence. Results showed that the positive picture-word condition increased positive affect more than the control and negative conditions. Participants in the positive condition also demonstrated enhanced performance on a behavioural task compared to the two other conditions. Compared to participants in the negative condition, participants in the positive condition provided more positive responses on a homophone task administered after 24h to assess the durability of effects. These findings suggest that a positive picture-word task used to evoke mental imagery leads to improvements in positive mood, with transfer to later performance. Understanding the mechanisms underlying mood change in dysphoria may hold implications for both theory and treatment development.     

Can Pragmatists be Institutionalists? John Dewey Joins the Non-ideal/Ideal Theory Debate

During the 1960s and 1970s, institutionalists and behavioralists in the discipline of political science argued over the legitimacy of the institutional approach to political inquiry. In the discipline of philosophy, a similar debate concerning institutions has never taken place. Yet, a growing number of philosophers are now working out the institutional implications of political ideas in what has become known as “non-ideal theory.” My thesis is two-fold: (1) pragmatism and institutionalism are compatible and (2) non-ideal theorists, following the example of pragmatists, can avoid a similar debate as took place between institutionalists and behavioralists by divulging their assumptions about institutions.