New Research From Psychological Science

Read about the latest research published in Psychological Science:

Costly Signaling Increases Trust, Even Across Religious Affiliations

Deborah L. Hall, Adam B. Cohen, Kaitlin K. Meyer, Allison H. Varley, and Gene A. Brewer

Cultures often have specific norms that members of the group are expected to follow. Although adherence to group norms generally increases within-group trust, it is not known how adherence to or violation of such norms is viewed by outgroup members. In a series of four studies, the authors examined costly signaling — the performance of costly behaviors that communicate commitment to the group — on perceptions of in-group and out-group trust. Christian participants viewed profiles or read vignettes describing Christian (in-group) or Muslim (out-group) individuals performing, or not performing, religion-based costly-signaling behaviors. Performing costly-signaling behaviors increased participants’ perception of trust regardless of the target individual’s in-group or out-group status. This suggests that the religious practices that define and differentiate groups can promote trust between them.

Survival Analysis of Adolescent Friendships: The Downside of Dissimilarity

Amy C. Hartl, Brett Laursen, and Antonius H. N. Cillessen

Why do friendships end? In the 7th grade, students completed friendship nominations using a roster that included the names of all the students in their grade. Students who were identified as having at least one reciprocated friendship completed the friendship nomination annually through the 12th grade. Less than 25% of 7th-grade friendships survived across the following school year, and less than 1% continued through the 12th grade. The researchers found that differences between friends in sex, peer acceptance, physical aggression, and competence in school predicted the occurrence and timing of friendship dissolution. These findings indicate that stability in adolescent friendships is a product of similarity between friends.

The Words Children Hear: Picture Books and the Statistics for Language Learning

Jessica L. Montag, Michael N. Jones, and Linda B. Smith

One of the main ways in which children learn language is by listening to the speech of others, with greater language diversity leading to better language outcomes. One important source of this language is the conversations parents have with their children; however, a second important source may be language children hear through the reading of picture books — something that more than 50% of parents do. Researchers examined the number of unique words in equal-length segments of parent-child conversation and picture books. The books contained more unique words than did child-directed conversational speech, demonstrating the importance of reading to children.