Okay, so let's think about this. Why is this answer not surprising to us? Men interested in short term relationships are more likely to put a high priority on immediate sexual gratification, in which case he is going to be more interested in assessing a woman's body. The body gives a lot of clues as to a woman's immediate fertility status, which is historically how men determined a woman's attractiveness, even if reproduction isn't a main concern in choosing sexual partners in modern times. Body shape (you know... T&A), in particular waist-to-hip ratio, can tell a man if a woman is already pregnant (effectively reducing her fertility potential to zero, since she is unable to conceive with him at the moment), and can otherwise give clues as to whether or not she is sexually receptive, how healthy she is, and how easily her body could provide for and handle the stress of pregnancy and breastfeeding.
Mathematically speaking, more men are interested in Sarah Shahi's face than her body. I was surprised.
Men looking for long-term partners, however, are going to be somewhat less concerned with a woman's immediate fertility and more concerned by her future reproductive potential. How many children is she going to be able to bear from now to menopause or death (whichever comes first)? Is it likely that she will die before menopause? At what age is she expected to go through menopause? How long is that from how old she is now? This is generally determined by age and overall health, which the authors argue is more readily determined by facial characteristics. High estrogen levels result in more feminine facial features, or "softness" of features, and youthfulness and health provide firm, clear skin. The authors choose to look at only biological factors here (and rightfully so), but I think there's also something to be said about long-term compatibility being more easily determined from the face, which more clearly expresses personality traits than body figure.
Granted, a lot of this stuff is just as easily if not more easily determined by chemosensory cues, but let's assume we're locking eyes across a crowded room, here. Do you approach or not? That decision is made before you ever get a chance to sniff the lady. There's also a lot of overlap between what you can determine from the face and from the body. The authors of this study tentatively decide that you can tell more about a woman's future reproductive value from the face and more about her immediate fertility from the body. I don't know that I 100% agree with that, but I'm willing to humor them. Let's look at the numbers, shall we?
"Frequency distribution of [face or body] choice by mating context and sex. Expected frequencies of box choice, based on average frequencies by sex, are indicated with dashed lines." [Modified from Confer et al, 2010.]
Men looking for short-term relationships were pretty evenly split in their preference to see a woman's face or body, whereas men looking for long-term relationships were more interested in a woman's face 75% of the time. I am surprised that the former group wasn't more heavily skewed towards the woman's body, however the definition of 'short-term' is not very clearly defined, and can mean very different things to different people. I have a feeling that if they added a 'one night stand' category it would paint a clearer picture. It should also be noted that the average age of participants in this study was right around 18 years old, which I would argue is an awfully early age to be asking people to determine the long-term relationship potential of a stranger.
You might be asking, "But Michelle, what about the ladies? What do they want in a partner?" If I could tell you what women want in a partner I'd be a very rich lady indeed. From the empirical evidence in this study, however, I can tell you that 18-year-old woman tend to prefer faces over bodies regardless of what type of relationship they are seeking. So drop that dumbbell and get your ass to plastic surgery! Okay, no, I'm joking, please don't do that. I can't stress enough the importance of a good moisturizer, though.
Confer, J., Perilloux, C., & Buss, D. (2010). More than just a pretty face: men's priority shifts toward bodily attractiveness in short-term versus long-term mating contexts Evolution and Human Behavior, 31 (5), 348-353 DOI: 10.1016/j.evolhumbehav.2010.04.002