The biological approach does not take into account the social, economic and environmental factors that play an important role in behavior and personality. For example, the biological approach would not be able to explain a person with extremely high intelligence if that person did not exhibit notably different brain functions or genetics. This person's intelligence may come from family factors or environmental factors, but the biological approach does not take this into account. Another example would be a patient suffering from mental depression, but with no family history of psychotic depression and a fully functioning brain. This rupture can result from work-related stress or from an interpersonal relationship, but again the biological approach does not take these factors into account.