The Boston University Twin Project (BUTP) is supported by Grant MH062375 to Dr. Saudino from the National Institute of Mental Health. The author gratefully acknowledges the families in the BUTP, and the BUTP staff and volunteers. Special thanks to Dr. Jeff Zapfe for his help with the Actical data.
Sources of Continuity and Change in Activity Level in Early Childhood
Article first published online: 22 NOV 2011
© 2011 The Author. Child Development © 2011 Society for Research in Child Development, Inc
Volume 83, Issue 1, pages 266–281, January/February 2012
How to Cite
Saudino, K. J. (2012), Sources of Continuity and Change in Activity Level in Early Childhood. Child Development, 83: 266–281. doi: 10.1111/j.1467-8624.2011.01680.x
- Issue published online: 25 JAN 2012
- Article first published online: 22 NOV 2011
Actigraphs and parent and observer ratings were used to explore genetic influences on continuity and change in activity level (AL) in early childhood. Over 300 pairs of twins wore actigraphs for a 48-hr period in the home and laboratory at ages 2 and 3. AL was genetically influenced at both ages with little evidence of differential heritability across age. For all measures, genetic influences contributed to phenotypic continuity. With the exception of the actigraph measure of AL in the home, new genetic effects emerged at age 3 indicating that genetic factors influence both continuity and change in AL in early childhood. Nonshared environmental influences were also a source of change in AL across the transition from infancy to early childhood.