© Marije Schmitz-Niehaus

My main interest is understanding human behaviour from an evolutionary perspective. I am particularly interested in evolutionary processes in contemporary populations. Currently, I focus on understanding fertility (the number of children an individual has) and fertility-decisions using a biosocial framework. I am also interested in the (mal)adaptiveness of such behaviour. 

In the past I have worked on very different topics largely concerning very different species. Mostly, I studied in the evolutionary relevance of human height. Throughout the animal kingdom, natural and sexual selection act on body size. In this research, I examined whether the same holds true for human body size, height. More specifically, I investigated if height is related to mate choice, intra-sexual competition, and ultimately biological fitness. I use a variety of methodologies in my research, ranging from online questionnaires and archival datasets to behavioural observations and experiments. In earlier days, I examined personality in rats (aggressive individuals are more impulsive), lateralisation in chickens (80% are ‘right-handed’), and intelligence in crows (much smarter than our beloved cats and dogs).