Walking in Your Siblings' Shoes: Older Siblings' Influence on Theory of Mind

Walking in Your Siblings' Shoes: Older Siblings' Influence on Theory of Mind

Saarah Safiq

University of Guelph

Older Siblings’ Influence on Theory of Mind

        Theory of mind is a term that defines the capacity to attribute states to oneself and others. It involves recognition that others may have intentions and ideas that are different from one's own (Sherwood, 2015). The “theory of mind” is viewed as a theory because conditions are not exactly observable. Instead, common paradigms are used to gauge whether the ability to infer states of others is established in young people (Premack & Woodruff, 1978). Though theory of mind typically begins to develop after age 2 (Sherwood, 2015), children ages 4 and 5 show theory of mind on common paradigm tests (Wellman, Cross & Watson, 2001). Theory of mind has been studied in chimpanzees. There are similar mental states both humans and chimpanzees may infer, including motive, intent and predicting (Premack & Woodruff, 1978). Theory of mind has been studied widely among children with autism (Baron-Cohen, Leslie & Firth, 1985). There are also studies on children cross-culturally, between China and the U.S., particularly because of the one-child policy that was previously enforced in China. While children from China tend to out-perform American children on all other indices of executive functioning, their performance on theory of mind tasks did not measure up (Sabbagh, Xu, Carlson, Moses & Lee, 2006). This suggests that having siblings might be a factor that fosters the development of theory of mind. The current study investigates whether, in fact, having older siblings leads to expedited development of theory of mind in youngsters.

Aims and Predictions of the Current Study

        The current study asks the question: Do children who have older siblings develop theory of mind faster than children who do not have siblings? It is hypothesized that children who have a greater number of older siblings will develop theory of mind at an earlier age than children who have no or fewer siblings. Specifically, children who have no siblings will develop theory of mind at a later time than those who have 1 or 2 siblings. Children with 1 sibling will develop theory of mind later than those who have 2.

Method

        Participants. Research assistants recruited families through community parenting groups, news paper advertisements, and word of mouth (see Appendix A). The research involved a cash incentive for participating children, which was collected by the parent. Participants’ parents each had a child or children between 4 and 7. We collected data from 315 participants with 105 participants per group. Groups were divided into those with no siblings, 1 sibling and 2 siblings. Any children with more than 2 siblings were excluded.