In 2020, psychologists from the State University of New York at Oswego looked at how heterosexual men and women perceived women with nipple erections. 

In part 1 of the study, participants were shown randomized slides with two sets of identical pictures of women – except for the fact that in some of the pictures the women had erect nipples, and some didn't. The participants were then asked to rate the photographed women on a series of 16 emotional and physiological states, including positive, negative, and sexually aroused states.

To make sure facial expression cues didn't influence participants, the faces of the women were obscured, while the levels of nipple erectness were scored by independent raters. Men and women were more likely to project positive emotions onto photographs of the women with erect nipples, while – to the surprise of no one – men projected more "sexy emotions" onto the photos.

Well, now part 2 of the study – published in Evolutionary Behavioral Science – is finally out, and we have more info on the effect of erect nipples on heterosexual men, and it turns out they'll go out of their way to be around them.

In the sequel – "The point of nipple erection 2: The effect of nipple erection on intended and expected altruism" – the team wanted to find out if these perceived emotional states had an effect on male behavior.

"For example," the team writes. "Would men be more willing to assist women with nipple erection as opposed to those without?"

As before, the heterosexual men were asked to rate pictures of women with and without nipple erections, as well as being asked a range of questions designed to test their change in attitudes, such as whether they would lend her $100, help her if her car was broken down, or provide tutoring sessions. The male group, it transpired, was much more likely to help the women with erect nipples, particularly when that help would require them to be in close proximity to the woman with erect nipples.

"Men perceived women with nipple erection as more deserving of altruism, especially if that altruism involved greater interaction with the woman, and they expected these same women to behave more altruistically toward them," the team wrote in the study of 421 college students.

"They also believed the women with erect nipples should be included in their social groups."

Meanwhile, heterosexual women did not perceive the women with nipple erections as being more deserving of altruistic behavior, "and did not want to include them into their social groups".

The team notes that the images of women used were all of "attractive" women – which could, of course, be open to all sorts of biases – and that no research has been done that includes variables such as facial expression cues, nor using photographs of women of different ages and body types.

[H/T: PsyPost]