In a world where there appear to be unlimited options to find a spouse competition for a partner can be severe. As the old adage goes not everything that glitters is gold. If you've always felt that people lie when presenting themselves to a possible spouse here's the evidence to back you up.

Two researchers from the University of Rochester's Department of Clinical and Social Sciences in Psychology and the Israeli-based Interdisciplinary Center Herzliya conclude in a new study published in the Journal of Experimental Social Psychology that when the possibility of sex looms people are more likely to change their attitudes and engage in deceptive self-presentation. To put it another way they conform embellish and occasionally lie.

The researchers Gurit Birnbaum a social psychologist and associate professor of psychology at the IDC Herzliya and Harry Reis a professor of clinical and social sciences in psychology and Dean's Professor in Arts Sciences and Engineering at the University of Rochester hypothesized that sexual thoughts—or to put it another way the activation of an individual's sexual system—would increase a person's efforts to manage first impressions bringing with it depressive symptoms.

They tested that theory on 634 heterosexual students (328 females and 306 males) with an average age of approximately 25. The researchers exposed one group to sexual stimuli and the control group to neutral stimuli over the course of four investigations. Participants in the study all of whom were students at an Israeli university then engaged with an opposite-sex stranger.

In Study 1 two study participants were asked to address a dilemma faced by a fake third person—whether to accept a job offer abroad or to decline the offer in order to stay close to family and friends. Both participants were given a specific viewpoint to argue in a face-to-face interaction—one for and one against the relocation overseas. Following then participants judged how much they outwardly agreed with the other participant's stance during the interaction. Participants who had been sexually primed were more likely to agree with a contradictory opinion promoted by an opposite-sex participant than participants in the control group (no prior sexual stimuli). The researchers view this conduct as a technique for making a good impression on the stranger boosting the chances of becoming closer to this individual.

The second study looked at whether study participants would adjust their reported preferences to conform to the ideals of a stranger. Participants were asked to fill out a questionnaire that examined their preferences in various life scenarios (for example "to what extent does it bother you to date someone who is messy?" or "do you like to cuddle after sex?"). Following that subjects were subliminally shown either a sexual or a neutral picture prime.

Participants were then told they would be taking part in an online discussion with another participant who was actually an insider—a member of the study team of the opposing gender. They examined an online profile that purported to show the insider's interests on a variety of topics. Following the reading of the profile participants were asked to develop their own profile which would be forwarded to the other participant and to complete their profile by evaluating the same things as those offered in the insider's profile.

The researchers discovered that even a non-conscious sexual stimulus (such as flashing an erotic picture in a flash frame inside an otherwise neutral video) caused individuals to adhere more to the preferences of a possible partner in a variety of life scenarios.

The third and fourth studies investigated whether participants would lie about the number of previous sexual partners. The researchers expected that people would minimize the number of partners they had in order to look more selected — or less promiscuous — to a future mate. To test the theory researchers had individuals discuss their total number of sexual partners with an attractive study insider over a discussion. They were then asked the identical question in anonymous surveys to provide the researchers with a true baseline. The results were clear: study participants who had been sexually primed were more prone to lie reporting fewer previous sexual partners to a possible match than those who had not been sexually primed.