This is a paper I submitted as a sophomore to EFB 480, Animal Behavior. I got an A. Pardon the horrible sentence structure and other mistakes, it was written at 3am.

***To those who say this is "old news," I took a concept, and actually looked into it. While it was often anecdotaly known that men often choose to leave space between themselves, I applied statistics to it and offer hard core evidence. And yes, I did actually write this.

Personal Space and Urinal Selection in Male Homo sapiens, by John Vanek (Nomadofthehills), SUNY College of Environmental Science and Forestry


Many human (Homo sapiens) males choose to avoid adjacent urinals to those in use by other males, as well as socialization while urinating. One explanation towards this distance males keep from one another is that it is simply risky to be close to another male. With external genitalia exposed, the reproductive potential of a male is at much higher risk than normal. In this paper I offer evidence to support this hypothesis, and suggestions for future study of this behavior. After hours performing this observational study, my results suggest that males do indeed show an inclination towards distance between each other while using urinals, based on an analysis of the categorical data using a chi square equation. While I found evidence to support my hypothesis, it appears that only reproductive aged males follow the personal space "rule," with examples of the elderly and prepubescent ignoring the social "rules" of distance and silence in the men's room. In addition, fathers seem to protect their sons from other males, by standing in adjacent to their progeny.


As a gregariousspecies, Homo sapiens nonetheless maintains a degree of personal space. This space is intended to provide safety, as it is in other species, and is expressed differently in many situations. Males tend to keep a further distance between each other than females, possibly in response to the danger another male poses. Testosterone, the primary androgen, is highly correlated with aggression, and the further away from another male, the safer one is. Observing males at a movie theater will show two close friends leaving a space between themselves when ample room is present. Crowded conditions force the personal space maintained by individuals to decrease, but those same males who would spread out in an empty theater will sit next to each other, however, reluctantly. In addition to the danger another male poses (an injury may lead to reduced reproductive success); staying too close to another male may send a signal detected by females indicating homosexuality. Evolutionarily, this is a pathologic condition, and a female would be reluctant to mate with what she believes to be a male who is not interested in fathering her children.

Men may be particularly protective of their personal space when their future reproductive success is more directly at risk: exposed genitals while using urinals in a public restroom. While females actively engage other females in conversation during utilization of restrooms for the maintenance or forging new social connections; their reproductive organs are internal, and no more exposed to harm than when not using a restroom. Common knowledge suggests males are largely silent, ignoring other males, even friends, when urinating in urinals not isolated by dividers, and will actively chose to leave distance between other themselves and other urinators. With reproductive success tied to the external genitalia, leaving them exposed to the mercy of other males is pathologic and simple actions such as ignoring other males and distancing oneself from other males expresses the result of an evolutionary cost benefit analysis. Males will aim to spend as little time as possible in the restroom; time spent in a bathroom is time spent away from females (and in closer proximity to dangerous males), and females are the key to reproductive success.

To minimize threat to the reproductive organs from other potentially aggressive, dangerous males, males distance themselves and do not acknowledge others while exposed. They choose the relative danger of urinals over the protection of a stall for the quickness they offer, allowing them to get out of the male only area as quickly as possible. Ideally, this should maximize mating with females (which cannot happen in a room filled with only other males), and protecting future chances to mate with females. I present a look at this spatial distancing during urinal use by male Homo sapiens. Assuming that males choose urinals over stalls, and prefer to distance themselves from other males during this process, I predict that human males would not choose to use a urinal directly adjacent to an occupied urinal.


I conducted this study primarily at the Carousel Mall in Syracuse NY, where the majority of my data were collected (n=34). The site was located on the third floor, the right men's restroom heading towards the cinema. This restroom contained five urinals with no dividers, spaced .3 meters apart. The urinal closest to the door was .3 meters shorter than the other four, a child urinal. Past the line of urinals was set of stalls, and 10 meters in front of the urinals was a counter with sinks and a wall length mirror. I stood at the end of the counter looking in the mirror to collect my data in order to disturb the subjects as little as possible (Figure 1). I recorded which urinal each male selected on 5 April 2008 from 17:00 until 22:00, and from 14:00 until 17:00 on 15 April 2008. In addition to this site, my partner recorded data in the same fashion from Marathon Central School (n=5), which also contained 5 urinals without dividers, on 5 April 2008, as well as several other locations, of which the data were not used in this paper due to small sample sizes and insufficient urinal numbers.

The data were organized into two categories: space and no space. Space refers to a male choosing a urinal that is not directly adjacent to a urinal occupied by another male. No space refers to an instance of a male choosing a urinal directly adjacent to an already occupied urinal. Only the instances of two males using the five urinals were analyzed in this test, but the other instances were still recorded, and are located in the appendix with the rest of the raw data. I preformed a Chi Square Goodness of Fit test on the data, with one degree of freedom and an alpha value of .05. In every instance (except for one) used for this analysis, the original male chose either the far left or far right urinal. I assumed that males who chose to leave space between the original male and himself had a ¾ chance to do so, as out of the five urinals, one was taken by the original male, and the adjacent urinal was off limits, leaving 3 urinals out of the remaining four. For males leaving no space, I assumed there was a ¼ chance, as the only option was the adjacent urinal. Using these assumed percentages, I calculated my expected values and was able to obtain a chi square value.


34 males chose to leave space, and 5 males chose to leave no space (Figure 2), resulting in a sample size of n=39. The one degree of freedom and alpha value of .05 led to a critical table value of 3.841, which is greater than the calculated chi square value of x2=3.08547 (Table 1). Due to this, I was forced to fail to reject the null, indicating that males will chose to leave space, as opposed to selecting an adjacent urinal to the original male.


The first male to enter the restroom invariably chose a urinal next to a wall. This may have been to limit the number of sides to watch for other males. Choosing a middle urinal, although closer to the door, risks having a male on both sides, two males are twice as dangerous as a single competitor. Many men also chose to bypass the first walled urinal, to use the far walled urinal. The urinal closet to the door in this case was much smaller, and the extra distance may prove more beneficial than being uncomfortable and more exposed by using a smaller urinal. Anecdotally, shorter men were more likely to use the smaller urinal.

By failing to reject the null hypothesis, the results support my original hypothesis that males choose to avoid urinals adjacent to another male. The observed values follow the expected values for higher frequency of males leaving space. Over 89% of males left a space, compared to 11% who chose to ignore the risks to their fitness, or so it looks at first. Four of the five instances of males ignoring the personal space associated with urinal use involve non reproductive members of society. Two of the instances involved a father and prepubescent son. In each case, the son chose a urinal closest to the wall, and the father took the urinal adjacent to him. This may have been to protect his genes in the case another male enters the restroom. The father's offspring is no threat to his own reproductive success, competition wise, and by protecting his son, the father is protecting his future genetic contribution to the species. If the father were to leave space between himself and his son, there is a much greater chance for a rival male to injure the boy or possibly kidnap him. Staying close ensures the boy's protection especially during a particularly vulnerable situation of danger to genitals in addition to the potential danger of simple somatic harm.

One of the five instances of no space involved two prepubescent boys. As their testosterone level is low, and they are not reproductive members of the species yet, they pose little threat to each other, reproductively. Similar to this, there was a case of two 70 year old plus men who used adjacent urinals. In addition, they were also the only two to not have at least one of them use a urinal next to a wall. It is possible that being well past their reproductive prime, they had little incentive to protect their reproductive success. With senescence comes a decrease in testosterone, and an increase in estrogen, leading to more female like social behavior. As with the prepubescent boys with increased estrogen, both groups of non reproductive individuals were very talkative during urination, in stark contrast to reproductive aged males, who aim to get in and out quickly, distancing themselves from other males. Talking wastes time in this area barren of females, and thus has little purpose for males of reproductive age, aiming to get back into the female inhabited area that is not the male restroom. Future studies may examine the difference in age and urinal spacing, or when more than two males enter the equation at time. They may also compare social interaction in both the men and women's room.