In this section, we will look at some of the ways in which heredity helps to shape the way we are. Heredity involves more than genetic information from our parents. According to evolutionary psychology, our genetic inheritance comes from the most adaptive genes of our ancestors. We will look at what happens genetically during conception and take a brief look at some genetic abnormalities. Before going into these topics, however, it is important to emphasize the interplay between heredity and the environment. Why are you the way you are? As you consider some of your features (height, weight, personality, health, etc.), ask yourself whether these features are a result of heredity, or environmental factors, or both. Chances are, you can see the ways in which both heredity and environmental factors (such as lifestyle, diet, and so on) have contributed to these features.

Evolutionary Psychology

Figure 1. Evolutionary psychology examines the connection between biological adaptation and preferences in mate selection.

Evolutionary psychology focuses on how universal patterns of behavior and cognitive processes have evolved over time. Variations in cognition and behavior would make individuals more or less successful in reproducing and passing those genes to their offspring. Evolutionary psychologists study a variety of psychological phenomena that may have evolved as adaptations, including the fear response, food preferences, mate selection, and cooperative behaviors (Confer et al., 2010).

Many think of evolution as the development of traits and behaviors that allow us to survive this “dog-eat-dog” world, like strong leg muscles to run fast, or fists to punch and defend ourselves. However, physical survival is only important if it eventually contributes to successful reproduction. That is, even if you live to be 100 years old, if you fail to mate and produce children, your genes will die with your body. Thus, reproductive success, not survival success, is the engine of evolution by natural selection.

Charles Darwin describes this process in the theory of evolution by natural selection. In simple terms, the theory states that organisms that are better suited for their environment will survive and reproduce, while those that are poorly suited for their environment will die off. There is a growing interest in applying the principles of evolutionary psychology to better understand lifespan development in humans.

Lifespan Development and Evolutionary Psychology

As we consider development from conception through the lifespan, there will be many opportunities to understand how evolutionary psychology enhances our understanding of development. For instance, women and men do differ in their preferences for a few key qualities in long-term mating, because of somewhat distinct adaptive concerns. Modern women have inherited the evolutionary trait to desire mates who possess resources, have qualities linked with acquiring resources (e.g., ambition, wealth, industriousness), and are willing to share those resources with them. On the other hand, men more strongly desire youth and health in women, as both are cues to fertility. These male and female differences have historically been universal in humans.

Just because a psychological adaptation was advantageous in our history, doesn’t mean it’s still useful today. For example, even though women may have preferred men with resources in previous generations, our modern society has advanced such that these preferences are no longer necessary. Nonetheless, it’s important to consider how our evolutionary history has shaped our automatic or “instinctual” desires and reflexes of today so that we can better shape them for the future ahead.

As we follow the journey of life, from conception to death, think about how the theory of natural selection and the concepts of evolutionary psychology can enlighten our understanding of why some automatic reflexes or instinctual desires are more common than others. Remember that the end product of the theory of evolution by natural selection is successful survival and reproduction. Can you think of some ways that the ultimate goal of reproductive success affects our selection of a mate, how we parent young children, why we are motivated to achieve certain goals, or what differentiates families with traditionally longer lifespans? In order to achieve reproductive success, the theory of evolution by natural selection states that organisms should be suited to their environment. Think about how different environments or cultures require different traits for successful survival and reproduction. Can you think of some ways that we may be changing to be better suited to our changing culture?