If you are thinking of asking for a promotion, a raise, or more vacation time, you might consider crying a little.

Hey, don’t blame me. It’s science from a new report from INSEAD business school titled Weep and Get More: When and Why Sadness Expression Is Effective in Negotiations.

According to Discover Magazine, researchers tested whether people who expressed sadness in negotiations were able to get a better deal. They did find that bursting into tears actually worked by making the other person feel sorry for the weeper, but only under certain conditions, such as those in which the person crying is perceived as having less power, or if the non-weeping person expects another future interaction with the weeping person.

Here’s the abstract:

“Although recently some research has been accumulated on emotional expressions in negotiations, there is little research on whether expressing sadness could have any effect in negotiations. We propose that sadness expressions can increase the expressers’ ability to claim value in negotiations because they make recipients experience greater other-concern for the expresser. However, only when the social situation provides recipients with reasons to experience concern for the expresser in the first place, will recipients act on their other-concern and, eventually, concede more to a sad expresser. Three experiments tested this proposition by examining face-to-face, actual negotiations (in which participants interacted with each other). In all 3 experiments, recipients conceded more to a sad expresser when, but only when, features of the social situation provided reasons to experience other-concern for the expresser, namely (a) when recipients perceived the expresser as low power (Experiment 1), (b) when recipients anticipated a future interaction (Experiment 1), (c) when recipients construed the relationship as collaborative in nature (Experiment 2), or (d) when recipients believed that it was inappropriate to blame others (Experiment 3). All 3 experiments showed that the positive effect of sadness expression was mediated by the recipients’ greater other-concern. These findings extend previous research on emotional expressions in negotiations by emphasizing a distinct psychological mechanism. Implications for our understanding of sadness, negotiations, and emotions are discussed.”

OK, this might work under those very specific circumstances. But I can’t in good conscious actually suggest you cry to get what you want at work. Even if it works, future interactions with that person will be awkward.

Here’s are some tips on how to ask for a raise without crying:

Ask when the company is doing well. Don’t ask if you know they can’t afford it, like during layoffs. Wait until you know they can.

List your accomplishments. This will demonstrate why you are worth more than you’re getting. Cite numbers, growth, improvements, that sort of thing.

Don’t threaten or give ultimatums. They might just tell you to take a walk, so don’t threaten to take one unless you’re ready to do so.

Don’t make it about what your needs. Focus in your accomplishments, not your needs. You’ll get a raise because you deserve it, not because you need it.

Ask later in the week. In his book, Buy Ketchup in May and Fly at Noon: A Guide to the Best Time to Buy This, Do That and Go There, Mark di Vincenzo writes that the best days to ask are Thursday or Friday, because “We’re most open to negotiation and compromise then because most of us want to finish our workweek with the least amount of conflict.”

Don’t ask on Wednesday. Di Vincenzo writes, “Unpleasantness and surliness tend to peak then, so try to avoid any situation that can lead to conflict.”

Now, what I really want to know is, have you ever gotten what you wanted with tears? What was it?