Twin Study of Self-Recognition in Toddlers

Paula Y. Mullineaux1, Deborah Finkel1, & Adam P. Matheny2

The development of self concept, as indicated by self-recognition, is one of the major developmental milestones of the second year of life. Developmental psychologists assert that self concept develops in concert with object permanence, the major achievement of Piaget*s first stage of development. In 1976, the Louisville Twin Study began videotaping infant twins in a series of play vignettes. One set of vignettes incorporates three standard measures of self-recognition, or self concept. The three mirror tasks include: a version of the rouge test, showing a toy behind the child, and asking the child to name the image in the mirror. In addition, because LTS uses a free standing mirror, we observed whether the child looked behind the mirror to find the perceived *other.* Videotapes for 20 MZ pairs and 20 DZ pairs at ages 18 and 24 months were examined for success or failure on the self-recognition tasks. The data were used to address 3 hypotheses: (1) do MZ twins demonstrate any delay in self-recognition, (2) is there evidence for genetic influence on the trait of self-recognition, and (3) what is the nature of the relationship between self-recognition and concurrent measures of mental development. Mental development was measured using the Bayley Mental Development Inventory. No evidence was found for any delay in self-recognition by identical twins. Depending on the measure, some evidence of genetic influences on self-recognition was found. Results suggest some genetic mediation of the relationship between self-recognition and mental development.

Address:   Paula Y. Mullineaux, Psychology Department, Indiana University Southeast, 4201 Grant Line Road, New Albany, IN 47150.

1Indiana University Southeast, New Albany, IN 47150. 2University of Louisville, Louisville, KY 40292.


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