From a young age, women are taught that the amount of time they have to start a family is limited. This time frame is called their biological clock. By their mid-30s, they’ll be past their fertility prime. By their 40s, the risks of having a baby with birth defects, such as Down syndrome, are higher. Although more women are waiting to have children despite their ticking biological clocks, a new study shows that some may subliminally trick themselves into wanting kids sooner, thanks to (strangely) having a ticking clock nearby.     

These clocks, researchers from the Florida State University found, primed women in the most subtle way to seek motherhood more quickly. Hearing the barely audible ticks of the clock’s second hand reminded women — particularly those with a lower socioeconomic background — subconsciously that their biological clocks were also ticking, moving them to want a child sooner, and to change the preconceived standards they held for a potential partner. Both of which are “central aspects of women’s mating-related psychology,” study author Justin Moss said in a press release.

The researchers based their study on the idea that a woman’s childhood years, socioeconomic status, and other environmental factors influence their attitudes toward childbearing and partner choice. But it’s questionable that having a ticking clock at home would influence a woman to seek just any partner and have children sooner. After all, having a kid isn’t the first and only thing on most women’s minds, even when a clock is ticking nearby.

For the study, however, 59 men and women were asked questions about the age that they’d like to get married and have kids, while a ticking clock loomed nearby. During this first experiment, the researchers also took into account each person’s socioeconomic status. For a second experiment, 74 participants were asked about the compromises they would make to their own standards just to have a child sooner — also while a clock ticked nearby.

They found that the ticking clocks worked especially well among women of lower socioeconomic status to influence their interest in having their first child at a younger age, while also lowering the priority they placed on men’s social status and long-term earning potential. The ticking clock didn’t work, however, among men, or women with a higher socioeconomic status.

In the press release, study co-author Jon Maner said that the “findings suggest that a woman’s childhood years can interact with subtle environmental stimuli to affect her reproductive timing during childhood.”

But the reason these women chose to have children sooner may not have been the ticking clock. Other research has already shown that women without college degrees tend to have children earlier and outside of marriage. These women also tend to be poorer. When that poverty is paired with the expenses of having a child around, it makes sense that the women from the current study who chose to have a kid earlier also lowered their standards for the men they would seek — these men could help in some child-rearing duties.

Overall, 21.8 percent of American children were living below the poverty line in 2012, according to the National Center for Law and Economic Justice. More often than not, it’s these kids’ moms who head the household.

Source: Moss J, Maner J. The Clock Is Ticking: The Sound of a Ticking Clock Speeds Up Women's Attitudes on Reproductive Timing. Human Nature. 2014.