Sadly, as so often happens, the source for the data is war, and not peace.

But we are now beginning to understand that the badly overused term "pheromones" is a broader part of communication than we wanted to believe.

The U.S. Army, in an effort to develop a non-injurious bomb has begun wondering in a concrete way if it could indice a wave of fear, even as its new weapons systems induce pain rather than injury. The military has backed a study on the "Identification and Isolation of Human Alarm Pheromones," which "focused on the Preliminary Identification of Steroids of Interest in Human Fear Sweat." The researchers collected sweat, urine, blood, saliva, ECG, respiration, and self-report measures in 20 subjects (n=11 males and n=9 females) before, during, and immediately following their first-time tandem skydive, as well as before, during, and immediately following their running on a treadmill for the same period of time. Measurements between the test (skydive) and control (exercise) conditions were made on consecutive days, each experiment precisely matched to the minute between subjects and between conditions to prevent diurnal confounds. The subjects also reported their emotions of a quiz form.

For most of the observed compounds of chemicals, men showed an increase during acute emotional stress. Women showed either no change or a decrease in emission of the compound. The significance of this difference will be lost on the military, but will be eventually debated by communicators. If men sesne fear from men as an olfactory inpout, and do not get the same report when near women, it is possible that many "early warning signs" of mis-communication are going to be ignored. This may be one of the "reasons" (there are never "excuses") for women feeling that in stress situtations with men they have to overreact in order to be heard, and why men report not being opposed in the preliminaries to violent behaviour.

In a 2002 study by the Ludwig-Boltzmann-Institute for Urban Ethology at the University of Vienna, subjects wore underarm pads while watching a 'horror' film -- Candyman -- or a 'neutral' documentary. Afterwards subjects were asked to try and distinguish between pads worn by people seeing each film. The results showed that they could.

But, the subjects thought the smell was aggression rather than fear.

This link between aggression and fear, or, going back to Konrad Lorenz on the subjects of coloration and motion, the idea that aggression is only a "natural" response to a perceived threat to wellbeing, points to an underlying problem with boys and guys. (I consider "men" to be different.) A permanent state of aroused aggressive impulses would spread by scent, would be the result of an underlying fear, and would not be understood the same way by females.

The sources of the fear?

Ah, that is another question, for many other posts.