The Handicap Principle. Why we behave extravagantly

handicap principle

In the ethological science, there are many original theories which surprisingly reveal some seemingly strange traits and behaviors. One of these theories, an extremely interesting one, called The Handicap Principle, has been suggested by the Israeli ethologist Amotz Zahavi. According to him, certain phenotypic animal traits or behaviors seem to be, on the first look, disadvantageous for the individual’s survival, being some kind of “handicaps.”

Let me exemplify it: the bushy tail of a male peacock is some kind of a “handicap,” which makes it difficult for him to move and exposes him to dangers; the massive horns of a male deer are also some kind of a “handicap,” because their growth and supporting is done by wasting important resources; as a rule, the variegated plumage, the audible voice and the displaying behaviors, specific to the males of various species of insects, amphibians, reptiles, birds and mammals, make it easier for them to be detected and renders them more vulnerable for the enemy.

Therefore, how can one explain the apparition and persistence of these “handicaps”, which have a negative effect in terms of survival, in the evolutionary plan? Shouldn’t those individuals who are less theatrical and more prudent be more favored?

The truth is that these “handicaps” are actually clues of physical excellence. The ”handicaps” illustrate the high quality and resistance of the individual’s genes; it is as if the males would send the following message to the females: “we can afford disadvantageous traits, because we are the most powerful and the worthiest and we can pay the price of these traits, so you should choose us.” And the females do choose males with a bushier tail, with larger horns, with a more variegated plumage, with a more audible voice, with a bolder behavior, because they also understand, on instinctual level, that only the vigorous and efficient males can afford having a “handicap”, to waste so much energy and to behave eccentrically.

Thus, even if the more precautious individuals and the less theatrical ones will have a life that would be probably longer, they will be disadvantaged in matters of sexual selection. On the contrary, the sexual selection has favored the individuals with “handicaps”. On the evolutionary level, those traits that ensure a succes in reproduction have perpetuated, even with the price of the individual’s life; it is important that the concerned one should succeed in having a greater access to females before dying [Zahavi, 1975, 1997].

In the category of such behaviors can be classified the cases of eating poisonous insects by some birds. For instance, the great bustard (Otis tarda) consumes blister beetles (Meloidae), in spite of the fact that they contain cantharidin, a highly toxic compound that is lethal in moderate doses. The male-biased consumption suggests that males could use cantharidin to reduce their parasite load and increase their sexual attractiveness.This plausibly explains the intense cloaca display males perform to approaching females, and the meticulous inspection females conduct of the male’s cloaca. A white, clean cloaca with no infection symptoms (e.g., diarrhoea) is an honest signal of both, resistance to cantharidin and absence of parasites, and represents a reliable indicator of the male quality to the extremely choosy females. Thus, the fact that males ingest these poisonous insects to increase their mating success, pointing out that self-medication might have been overlooked as a sexually-selected mechanism enhancing male fitness [Bravo et al., 2014]. Consumption of toxins is a very risky behavior, but this apparent handicap proves advantageous for strong males.

Humans have inherited these kinds of behaviors. But in the conditions of contemporary social life, an incalculably bigger variety of ways in which individuals highlight their potential has appeared. Today, “handicaps” are the exaggerated luxury, snobbism, crazy risk, extreme sports, bohemian life, hypertrophied muscles, eccentric jobs, intellectual hedonism, scientific and artistic occupations, acts of courage or of altruism and philanthropy, as well as corpulence or another vicious way of life. These are processes which consume inner resources; they are not economical. However, only the men that have a special physical, statutory or intellectual potential can afford it.

Only those who have good genes can afford “handicaps,” thus displaying they genetic dowry and becoming attractive (just like in the witticism which says that “the only people without vices are the one who cannot afford them”). The material, physical or intellectual excess is perceived as a demonstration of men’s highly competitive quality and capacity. And even if many “handicaps” from the contemporary society don’t directly reflect the genetic quality of individuals anymore, we continue to instinctually react to these bluffs that are being displays as some kind of flags of an authentic quality [1].

One could watch from a “handicap’s” perspective, as it has been already mentioned, the bohemian life of Rock Stars. The messy lifestyle, drug abuse, sleepless nights, suicidal inclinations – all these cause a lower life expectancy in musicians, many of them becoming, post-mortem, members of the so-called “club 27”, the club of the celebrities who died at the age of only 27 years old [2]. Generally speaking, it has been found that Pop Stars live, on average, 25 years less than simple people [3]. However, during their short lives, they are extremely popular with the public.

Men, in particular, are the ones who take advantage of their status as celebrities in order to have sexual intercourse with women. Music seems to be the most elaborate and sublime courtship signal that ever evolved. ”By the very act of playing, a musician breaks the ice with a pool of possible mates. The better the music, the bigger that pool. The better the musician, the more audience members will find him or her attractive”, said the evolutionary ecologist Rob Brooks [4]. The bohemian life and the profession of musician are perceived, evolutionary speaking, as a “handicap” and are attractive for women.

By the way, Charles Darwin first argued that birdsong and human music, having no clear survival benefit, were a products of sexual selection through mate choice. Some experiments provide empirical support for the sexual selection hypothesis of music evolution by showing that women have sexual preferences during peak conception times for men that are able to create more complex music. These results suggest that women may acquire genetic benefits for offspring by selecting musicians able to create more complex music as sexual partners [Charlton, 2014].

Here is another proof that what appears to be a “handicap” proves to be an indication of quality. The bohemian, disorganized and short life of singers is compensated by the multitude of sexual contacts that they have. The Handicap Principle still rules.

© Dorian Furtună, ethologist


Photo: Alter Bridge / from Flickr /
1. Handicap principle //
2. Why So Many Rock Stars Die at 27, Explained by Science // By Zachary Stockill. Music.Mic. May 20, 2014 /
3. The real reason pop musicians die young // Adam Epstein. Quartz. October 28, 2014 /
4. Get laid or die trying: how rock stars get their kicks in // by Rob Brooks. The Conversation. 19 June 2011 /

• Bravo C., Bautista L.M., García-París M., Blanco G., Alonso J.C. Males of a strongly polygynous species consume more poisonous food than females // PLoS One. Vol. 9(10). 2014 Oct 22. e111057. doi: 10.1371/journal.pone.0111057. eCollection 2014.
• Charlton B.D. Menstrual cycle phase alters women’s sexual preferences for composers of more complex music // Proceedings B. Volume: 282. Issue: 1802. March 2015. DOI: 10.1098/rspb.2014.0403
• Zahavi A. Mate selection – a selection for a handicap // Journal of Theoretical Biology. Vol. 53 (1). 1975. P. 205-214.
• Zahavi A. The handicap principle: a missing piece of Darwin’s puzzle. Oxford: Oxford University Press. 1997.