Interesting article someone pointed out in European Journal of Social Psychology: Seeing women as objects: The sexual body part recognition bias. The basic idea is to use a psychophysics-type perceptual experiment to explore whether people looking at men and at women process them differently. If perceiving people "as objects" makes a difference to the cognitive processes involved, then that should be detectable.
There's plenty of evidence about our society's exaggerated emphasis on female body image, and the consequences of such objectification. What the researchers do here is use an experiment in which participants are shown images of men and women (either complete or partial images), and ask them to do a kind of spot-the-difference task. They find people get different percentage-correct scores depending on whether it's an image of a man or a woman one is looking at.
The researchers discuss this result as relating to objectification of women, and I think that's broadly OK, but there's an extra hop that I think is glossed over. A tweet summarised the research as "People perceive men using global processing, but women with local processing" but it would be more correct to say "People perceive images of men using global processing, but images of women with local processing". (It's not just the 140-character limit at fault here, the research paper itself makes the leap.)
The point is that the participants were reacting to 2D images, rather than real physical presences of men or women. Now, you might think, is that an important difference, or just quibbling? I'm not claiming that the results are wrong, and I'm not even claiming that the results don't tell us something about objectification of women. But the difference between looking-at-people and looking-at-images is important here since it relates closely to the claims being made - and this highlights the complexity of making measurements of socially-embedded cognitive processing.
Here's why I think it's a difference: In our everyday lives we see "3D" men and women. We also see "2D" images of men and women. So there are four pertinent categories here: 3D men, 3D women, 2D men-images and 2D women-images. We have absorbed general impressions about these four categories from out experiences so far (whether those "categories" are categories we use ourselves is beside the point). It's well known that there are more and different images of women than men, used in advertising and other media. As a person develops they see examples of all four categories around them, and they might learn similarities and differences, things that the categories have in common or not.
[Edit: Maybe a better way of putting it is inanimate-vs-animate, not 2D-vs-3D - see comments]
So, it's reasonable to expect that an average person in Western society is more familiar with objectified images of women around than of men. (Note that I do not claim this state of affairs is OK! I just claim that it's the average person's developmental environment.) It's easier to deal with familiar categories than unfamiliar ones. So we'd expect people to have better processing when presented with 2D body-part-images of women - and it probably correlates with their visual processing of real-life people, but that's not certain and it needs to be tested.
Am I claiming that the research should not be trusted? No. It looks like a decent and interesting experimental result. But the authors make a slight leap, which we should treat with caution: they imply that their statistically significant result on how people visually process 2D-images-of-men and 2D-images-of-women transfers directly to how people visually process men and women in the flesh. Personally I would expect that people's perception of "3D" men and women probably partly generalises from the image perception and partly doesn't. (There might be existing research on that; comments welcome.)
And obviously it's much harder to conduct large experiments by showing people "glimpses of real live men/women" rather than images, so there's a good reason why such research hasn't yet been done.
But that's good news right? - more research needed ;)