A team of researchers at Cornell University recently studied the speech patterns of 52 convicted murderers, 14 of them classified as psychopathic, and came up with some intriguing results. The team asked the murderers to describe their crimes in detail, recorded the conversations, then converted the speech into text. Their discovery? Psychopaths — who make up an estimated 1 percent of the population and are "profoundly selfish and lack emotion" — tend to use identifying speech patterns. Sure, these verbal tics won't always help you spot a "crazy person during a short encounter at a bar," says Cassie Murdoch at Jezebel, but they might help experts zero in on potential offenders and strategize interrogations. What they should listen for:

1. Cause-and-effect statements
When discussing their actions, says Wynne Parry at Live Science, psychopaths are more likely to use subordinating conjunctions, like "because" and "so that," suggesting that they believe their crimes had a logical cause and effect, something that "had" to be done to achieve a goal.

2. A focus on food
Researchers found that psychopaths use an inordinate number of words related to basic needs such as eating, drinking, and money. According to the International Business Times, "psychopaths often included details of what they had to eat on the day of their crime" — perhaps revealing their "predatory nature."

3. A high frequency of "ums" 
Psychopaths use a lot of disfluencies when they speak, like "uhs" and "ums." It isn't, however, just because they're fumbling their words. According to lead researcher Jeffrey Hancock, "we think the 'uhs' and 'ums' are about putting the mask of sanity on."

4. An absence of remorse 
The subjects shied away from any topics that would indicate a moral compass, including talk about religion or family, which are things that "nonpsychopathic people would think about when they just committed a murder," says Parry.

5. A lot of past tense
Psychopaths are more likely to speak in the past tense than the present tense. Researchers believe this is a symptom of psychopaths' "psychological detachment."

Sources: IBT, Jezebel, Live Science