People suffering from diaphoraphobia get upset whenever others don’t think or behave in the accepted standard way of their particular group or culture, and even if they only look different. They may experience an irregular pulse, excessive sweating and heart problems. Reactions range from avoiding and ostracising these other people to expelling and even persecuting them.

The reason behind this phobia remains unknown, as well as its origins. While evolutionary psychology generally tries to explain phobias as adaptations to the environment which lead, even if only temporarily, to an evolutionary advantage, this definitely can’t be the case with diaphoraphobia since the condition itself prevents evolution and promotes inbreeding. Diaphoraphobics would have opposed man-made fires and the wheel as much as vaccines and the Internet.

We can safely conclude that the prevalence of this phobia has significantly slowed down human progress because, with diaphoraphobics being the vast majority, any improvements are being rejected, and anybody bringing these improvements about has to be strong-willed, self-assured and ready to stand out and make enemies. And even when they are, they may still be silenced and their ideas suppressed.

Diaphoraphobia incorporates a number of other phobias which until recently received a separate diagnosis, such as xenophobia (fear of foreigners), ethnophobia (fear of other races), Palestinophobia (fear of Palestinians), homophobia (fear of homosexuals), technophobia (fear of new technologies), sinistrophobia (fear of left-handed people) and autismophobia (fear of autism and autistic people).

While outsiders and group members of diaphoraphobics who appear different are dealt with in the prescribed manner of the group (from being avoided to being lynched, depending on the culture), family members showing signs of being different are usually dealt with in other ways. We know that many of them were killed or abandoned in ancient times, and they have been kept as an embarrassment in the basement or dumped into institutions for the past centuries. While this custom continues, a more recent approach is to treat their differentness as a disability and try to ‘cure’ them by suppressing their strengths and destroying their potential, such as forcing left-handed children to use their right hand for writing, eating etc, or breaking autistic children by subjecting them to demeaning procedures like Applied Behaviour Analysis in order to make them copy accepted standard behaviour and appear ‘normal’.

There is no known treatment for diaphoraphobia, one of the main problems being that most sufferers do not consider their condition a disorder and point out that they’re in the majority, which in their opinion makes them right. Studies suggest that diaphoraphobia is less common amongst atheists and agnostics, and that education and exposure to other cultures can contribute significantly to a reduction of the symptoms.