Australasian Science: Australia's authority on science since 1938

Midlife Crisis in Great Apes

By Magdeline Lum

Chimpanzees suffer a midlife crisis, and psychologists explore why we get itchy when we see someone else scratching.

The midlife crisis is no longer the exclusive domain of humans. A study of 508 chimpanzees and orangutans from zoos and research centres throughout the USA, Canada, Singapore, Japan and Australia has found that they also experience a midlife crisis, indicating it could be inherent in primate biology rather than something specific to human society.

Caretakers and other observers were asked to complete a questionnaire to assess the well-being of the apes under their care. Questions were subjective assessments of how the apes reacted in social situations and level of enthusiasm and success in completing tasks.

The final question asked keepers to imagine themselves as the apes and how happy they would be if they were that ape for a week. This was done for each ape, from infants to the older members of the family group.

When the results were collected and analysed, the contentment levels of middle-aged apes were comparable to humans between the ages of 45–50. There was no doubt they were experiencing a midlife crisis.

This suggests that the midlife crisis may be something that has been passed through evolution rather than something caused by the pressures and troubles of modern life.

However, it is not clear what benefit the midlife malcontent would provide. One suggestion is that it may spur a family group to shift towards more attainable goals to increase satisfaction levels.

Whatever the case may be, more research is needed.

Scratching is Catching

A new study published in the Proceedings of the National Academies of Science has found that seeing someone else scratching is enough to induce itchiness. In fact, the urge to scratch is more contagious than other socially contagious behaviour like yawning and laughing. Of the volunteers who saw videos of other people scratching, 64% scratched themselves.

When it comes to contagious yawning studies, 40–60% of respondents yawn while a contagious reaction occurs 47% of the time with laughter.

The reason why itching, smiling and head nodding is contagious comes down to how we experience emotions. Smiling and head nodding is a response to our empathy impulse. However, catching an itch may signal someone’s inclination towards having negative feelings.

Of the 51 participants in the study, 18 had their brains scanned to see how they responded when viewing videos of people scratching or tapping themselves. When they viewed people tapping, not any of them felt the urge to scratch but one participant did feel the need to tap. When videos of people scratching themselves were shown, the respondents reported feeling itchy and researchers urged them not to scratch.

The impulse to itch triggers a cluster of regions throughout the brain known as the itch matrix. When the neuroscientists analysed the scans, the level of itch matrix activity was proportional to the intensity of the itchiness reported by the volunteer.

All of the participants in the study took part in personality inventories to measure traits of empathy, extent of extroversion, agreeability, conscientiousness, openness and neuroticism. In previous studies in contagious behaviour, psychologists have concluded that people with a high degree of empathy tend to display mimicry of behaviour.

However, when it comes to itching, the results of this study revealed that a person who caught an itch was less likely to be someone who reacts with compassion to someone else’s troubles. Participants who felt the need to scratch were also likely to have a higher level of neuroticism.

Understanding how itching is related to negative feelings could lead to improvements in the treatment for conditions that cause severe itching like eczema. It may also help people suffering chronic itching sensations from which there is no underlying cause.