Do different measures tap the same genetic influences? A multi‐method study of activity level in young twins
In: Developmental science, Band 12, Heft 4, S. 626-633
ISSN: 1467-7687
Abstract Activity level (AL) is a highly salient feature of child behaviour that has been linked to developmental outcome. Twin studies of parent‐rated, observer‐rated and mechanically assessed AL in childhood find that AL is genetically influenced. Few studies, however, consider whether different methods of assessing AL have a shared genetic etiology. Those that do, confound methods and situations. The present study examined whether actigraph and rater‐based (parent, observer) measures of AL tap the same genetic influences in a sample of 312 2‐year‐old twin pairs. Methods were studied within the same situation, thereby controlling for situational influences on AL. The genetic correlation between actigraph and parent‐rated AL in the home was .38, indicating modest genetic overlap between the two methods. In contrast, the correlation of genetic effects on actigraph and observer‐rated AL in the laboratory was .95, indicating that both laboratory‐based measures of AL are influenced by the same genetic effects.