Genetic and Environmental Influences on Individual Differences in Frequency of Play with Pets among Middle-Aged Men: A Behavioral Genetic Analysis.
Jacobson KC, Hoffman CL, Vasilopoulos T, Kremen WS, Panizzon MS, Grant MD, Lyons MJ, Xian H, Franz CE. Genetic and Environmental Influences on Individual Differences in Frequency of Play with Pets among Middle-Aged Men: A Behavioral Genetic Analysis. Anthrozoos. 2012 Dec; 25(4):441-456.