Genetically-determined abnormal behavior in dogs: Results of behavioral tests

Starting with relatively stable and with very timid purebred pointer stock, we have accumulated data on exploratory activity, reactions to a loud noise, and reactions to friendly and threatening humans which demonstrate clear-cut strain differences. These differences appear as early as 2 months on some tests, and later at early maturity on others. A general factor of fear or timidity explains most of the atypical behavior of the unstable animals. Further, the consistency of results over three generations of offspring suggests a relatively simple mode of autosomal inheritance.