Darwinian Happiness: Evolution As a Guide for Living and Understanding Human Behavior, ISBN: 0878501592, is a 2002 book by the Norwegian biologist Bjorn Grinde from the Norwegian Institute of Public Health . He argues that human emotions find their cause in evolution and offers ways by which we can use this for our advantage.

More specifically, mammals are equipped with a nerve system that enables them to distinguish not only between pleasant and unpleasant sensations, but positive and negative experiences in general. While the biological term fitness refers to the capacity to create offspring, happiness (or quality of life) is, at least in a biological perspective, a question of the qualities of the experiences our nervous system offers us.

In order to improve these experiences there are two main principles to consider:

1. To utilize the rewarding sensations the brain is designed to offer in a way that gives optimal long-term benefits; and, similarly, to avoid punishing sensations.
2. To avoid stress and maladaptive ways of living in order to have a healthy mind with optimal potential for positive experiences.

As to the first principle, humans may actually have been equipped with more powerful positive and negative sensations, compared to other mammals, due to our capacity for free will. That is, evolution might tend to add stronger incentives for behavior benefitting the genes in a species with a powerful free will; as otherwise, the free will could easily result in unfavorable behavior.

As to the second principle, it may be added that, as a rule of thumb, we ought to adapt our way of living to how we are designed by evolution to live. Current ideas in evolutionary medicine and evolutionary psychology suggest that mismatches between the environment of evolutionary adaptation and the present way of living may cause somatic and mental health problems. Such adverse mismatches, referred to as discords, are obviously detrimental to quality of life. For example, present childcare practices may induce excessive anxiety in infants, which again may contribute to the high prevalence of anxiety disorders in adults.