Hunger makes you reckless: if animals grow up under difficult living conditions, they take greater risks later in life, a new study shows. Accordingly, the willingness of living beings to take risks is in part innate, but individual development in the first years of life also plays a decisive role. Whether we humans react in a similar way has yet to be investigated.
Animals in the wild are constantly exposed to life-threatening risks: while they are exploring habitats in unknown terrain or looking for new sources of food, they are constantly at risk of being caught by predators. Not infrequently, survival even depends on a decision. How the animal decides whether to take a risk or rather to avoid it, is very individual.
Willingness to take risks partly innate
“Just as there are more cautious and daring contemporaries among us humans, there are also animals of a kind who are less or more willing to take risks,” says Holger Schielzeth from the University of Jena. In order to find out to what extent the individual development of the animals plays a role, a research team led by Schielzeth and first author Nicholas Moran from Bielefeld University has now carried out a meta-study.
It was previously known that the willingness to take risks depends to a certain extent on the genetic makeup of living beings. But the living conditions and experiences of individuals also seem to have an influence, the researchers suspected. “On the one hand, one could assume that animals that are always doing well and are therefore in better condition have more to lose,” says Moran’s colleague Klaus Rheinhold. Therefore, they may be less willing to take risks. On the other hand, better living conditions could conversely mean that these animals can escape a risky situation more easily and therefore take more risks, speculated the scientists.
To test their hypotheses, the research team evaluated more than 120 experimental studies with more than 100 animal species – including, for example, studies on spiders, insects, crabs, fish, amphibians and birds. All individual studies had in common that the animals had experienced phases of good or poor food supply and that their willingness to take risks was measured in later life.
Bad care makes you brave
The result confirms: A poor supply condition during the growing up causes the animals to take higher risks later. According to the study, the willingness to take risks increases by an average of 26 percent if the animals were starved early in their development. For example, the researchers found that “fleeing to a new environment was more frequent in poorly cared for groups. This could be an indication that, in contrast, better cared for animals are pursuing the strategy of using more places of refuge. “
The connection between the poor care in the young animals and the willingness to take risks does not only apply to the migration to new surroundings: All the behavioral contexts examined – including risky foraging for food and exploring new places – showed similar results. The results were independent of the respective animal species and also the relationship of the animal species – the effect varied only minimally. “This result surprised us in its clarity,” says Moran’s colleague Schielzeth. The experts summarize that the fearlessness is due to a not inconsiderable extent to individual development. According to the ecologists, this connection could – at least to a certain extent – also exist in humans, since humans are also an animal species. Further studies should provide evidence of this.
Source: Friedrich Schiller University Jena, Article: Biological Reviews, doi: 10.1111 / brv.12655