Mirroring the marked sex difference in infant interactions and children’s toy preferences, male monkeys interacted significantly less with plush toys than did female monkeys. By contrast, males and females interacted with wheeled toys comparably, displaying no reliable sex differences. As is the case with sex differences in children’s toy preferences, only male monkeys showed a significant preference for one toy type over the other, preferring wheeled over plush toys. Unlike male monkeys and like girls, female monkeys did not show any reliable preference for either toy type.
Which doesn't seem to imply much, especially since many human males (and females!) tend to enjoy Warhammer-esque figures and action figures anyway. In point of fact, the evidence that humans prefer them for the intellectual qualities associated with them shows we have a higher intelligence which can deal with and ignore our primal instincts anyway.
There are many citations in there. I don't remember who the researchers were though.
[Citation needed]. What you're seeing in school is very likely the effect of early age socialization effects. Which can go both ways, if you look at other cultures, such as Iceland [1]. You may also want to familiarize yourself with the concept of "stereotype threat" [2].
> You never hear of the need to get more male nurses, or primary teachers and that is generally not viewed as a problem.
As a matter of fact, this is a source of concern in the relevant circles [3, 4]. For example, much has been written about boys not having enough male role models among teachers in schools. It just doesn't get much coverage in the media because, well, these are considered low-end jobs that few people other than those involved in nursing and teaching care much about. In fact, that is a major theme: If a type of job is dominated by women, it's likely to be poorly paid (stereotypically male jobs can go either way).
[1] http://content.time.com/time/magazine/article/0,9171,1032361...
[2] http://en.wikipedia.org/wiki/Stereotype_threat
[3] http://www.edutopia.org/male-teacher-shortage
[4] http://www.cbc.ca/thecurrent/episode/2013/02/21/is-the-short...