Boys' toys and games

Kim Wallen, a psychologist at Yerkes National Primate Research Center, found in her study that male rhesus monkeys played with model dump trucks and other wheeled toys, over plush dolls.

[1][non-primary source needed] Infant boys and girls as young as 9 months old have been found to display stereotypical toy preferences, suggesting that there are biological and environmental factors which appear very early in development.

After the subjects were shown one of the images, they were asked to pick whether a boy or girl would play with a selection of toys such as a baby doll, jet fighter, tool kit, tea set, etc.

These toys can also often blur the lines of the man-machine dichotomy, with action figures that represent males as machines on a range from technologically enhanced humans to cyborgs to sentient robots.

Tomy's Z-Knights toys introduced terms related to computer technology, in effect of masculinizing them by using humanoid robot characters named like Megahertz, CPU, and Kilabyte (kilobyte).