No nonsense, dry like the Sahara, but manages a difficult exercise. In an era where social constructivism flies high, this book is a summary of the research, dry conclusion after dry conclusion, citation after citation, of how very biological factors such as hormones, physiology, prenatal exposure and such influence human behaviour. Animal studies are mentioned as well. Conclusions are sometimes contextualised which helps to understand what the stats say and don't say.
The book is however not essentialist, it leaves room where room needs to be left to consider the influence of culture, but also doesn't beat around the bush when the science is pretty clear on the influence of biology on behaviour (like gendered toy choices in children and even primates) - which is an equilibrium that's not easy to achieve.