The behavioral characteristics of an individual are determined by its genes and by its physical and social environment. Not only the individual’s early life and current environment is of importance, but also the environment of previous generations. Through epigenetic processes, stress in parents and even grandparents can translate in changes in behavioral and physical characteristics of the offspring. This can also result in an increase in damaging behavior, such as feather pecking in laying hens. We have recently shown that stressed flocks of laying hen parent stock lay smaller eggs and that the offspring that hatched from these eggs were more fearful and showed more severe feather pecking already at one week of age. This effect depended on the genetic background of the hens: it was much more pronounced in the white laying hens than in the brown birds. Apart from epigenetics, also maternal hormones excreted before egg-laying or during pregnancy have effects on behavioral development of the offspring. Recent studies even indicate that epigenetic and hormonal effects may go hand in hand, where parental stress leads to changes in gene expression in genes involved in hormonal responses. The environment in which an individual is born and in which it spends its first weeks of life also has considerable impact on behavioral development. Absence or presence of maternal care has been shown to have strong effects in laying hens: we found that maternal care resulted in birds that were less fearful and developed less damaging behavior when they were adult. In these experiments, we also studied effects of genetic selection on low mortality in group housing. We found that effects of selection on low mortality and of maternal care were additive in most cases, with birds selected for low mortality and reared with a foster mother having the best performance. This illustrates that in our approaches to breed and rear animals for good performance in group housing systems, an approach where genetic selection is combined with improvement of rearing and housing conditions of both parent stock and offspring has the largest chance of success.