top of page

Survival Of The Kindest

You’ve probably heard of the ‘phrase the survival of the fittest’ as taught in most biology and some psychology classes.It was initially put forward by Herbert Spencer in his book, Principles of Biology, after reading naturalist Charles Darwin’s work. Darwin borrowed the phrase and used it in his book titled On The Origin of Species (1). It essentially means that the organisms that best adapt to their environment have an increased chance of reproducing and passing on their genes (2). Before the term, Darwin had described it as natural selection after studying plants, animals, and fossils in South America along with islands in the Pacific for five years.

Natural selection includes three elements; variation, reproduction, and heritability. Variation allows an individual to have traits that help them better adapt to their environment, and thus survive. This is caused by random genetic mutations. As the individual survives, it can reproduce by selecting the best-fit mate or by being selected as a mate, and pass on the trait to offspring. Overtime, the trait becomes more common in the population.

There’s a famous dilemma faced by almost all individuals when asked ‘why do all giraffes have long necks?’. The answer is generally ‘their genes adapted to be able to reach the leaves at the top.’ However logical this may sound, the considered correct answer is that a random genetic mutation caused a giraffe to have a longer neck among short-necked giraffes, allowing it to reach higher leaves and as a result, survive and pass on the trait. The frequency of its alleles, which are different forms of the same genes, increased in the population, and since the long-necked giraffes kept surviving and the short-necked failed to do so, short-necked giraffes were eliminated from the population. Disruptive evolution was what Darwin called the process.

If only the organisms have to think about themselves on a continuous basis to be able to survive, why do they engage in acts of kindness? This was a question that puzzled Darwin as well. One of the first hypotheses that were put forward was that kindness benefitted ‘group selection’ or simply, increased the chance of survival of the group or the species (3). If an organism helps their relative with shared genes survive and thus pass on its genes, it indirectly helps its species’ survival. Nonetheless, this theory fails to explain why unrelated individuals show acts of kindness to each other.

This was further explained by two other theories. The first is reciprocal altruism by Trivers, 1971. He explains this as ‘altruism that occurs between unrelated individuals when there will be repayment (or at least the promise of repayment) of the altruistic act in the future’ (4). For example, smaller fish called Remora clean the shark’s teeth, and in turn, sharks refrain from eating them. This is experienced by humans as well, at all times. Emotions such as gratitude and sympathy, and maybe even guilt, may have the evolutionary aim of curating symbiotic relationships.

While reciprocal altruism involves “repeated encounters between the same individuals allow for the return of an altruistic act by the recipient” (5), indirect reciprocity is not built on the basis that two individuals should ever meet again. In humans, acts of kindness between strangers have been observed to occur when the people that receive kindness have been observed to be engaged in acts of kindness before. As a result, people become motivated to be kind in hopes of being on the receiving end in the future.

Several theories have been proposed to explain the reason for the act of kindness, but all of them agree on the fact that it is, and has been, evolutionarily beneficial. For countless species, kindness, disguised by the types of symbiosis, has been the reason of survival through competition.

Works Cited

1 - Encyclopædia Britannica, inc. (n.d.). Survival of the fittest. Encyclopædia Britannica. Retrieved July 25, 2022, from

2 - Allott, A., & Mindorff, D. (2014). Ib Biology. Oxford University Press.

3 -Psychology | January 1st, 2015 1 C. (n.d.). We are wired to be kind: How evolution gave us empathy, Compassion & Gratitude. Open Culture. Retrieved July 25, 2022, from

4 - Reciprocal altruism. Reciprocal Altruism - an overview | ScienceDirect Topics. (n.d.). Retrieved July 25, 2022, from

5 - Nowak, M. A., & Sigmund, K. (n.d.). Evolution of indirect reciprocity by image scoring. Nature News. Retrieved July 25, 2022, from



bottom of page