This is true only to a point. Many may be good at math, but they end up studying English or philosophy. One's behavior is not directly determined by the abilities their genetics endow upon them. The nature-nurture debate has been around for many years, and maybe it will be partially solved once the human genome is decoded. The current issue is to decide what is classified as an ability and what is a behavior.
Most genetic influences take the form of abilities.
These capabilities that each of us have may indirectly influence our behaviors, but they do not directly control or result in certain behavioral characteristics.