Cultural evolution, the adaptive change of a culture to recurrent env t pressures mainly psychological forces) > product of human intellect and physical capacity. Lifestyle, the aggregate bhvr of a person; they way in which they leads their life. Cultural evolution has offered the luxury of diff lifestyle alternatives but also threats and injuries to our health and safety. Although the consequences of unhealthy lifestyle bhvrs have obvious negative biological implications, the bhvrs themselves can be acq d and maintained by both biological and psychological factors. The law of effect: bhvrs that produce favourable consequences tend to be repeated and those of unfavourable are not repeated (eating, exercise, rest) > but unhealthy bhvrs have reinforcing consequences in the short run and damaging consequences in the long run enjoy now, suffer later = teen smoking. Stress, a pattern of physiological, bhvral, and cognitive responses to stimuli (real or imagined) that are perceived as endangering one s well-being.