Let’s imagine that you’ve achieved the millennial dream and your new Etsy shop has begun to really take off. Apparently, your idea of making jewelry out of recycled fidget spinners really resonates with people.

Up until now you’ve worked alone to run your business: you design the products, you make the jewelry, you handle advertising, you package and deliver your orders, you do all of the customer service, etc. You quickly realize, however, that if you want to make your business larger, more productive, and more competitive you should find some other people to help you out.

So, now you’ve brought in a few friends and the big question becomes: who does what? For the most part, everyone is capable of performing any of the tasks needed to run the business. Consequently, you could either teach everyone every task or you could delegate one specific job to each person. Both options have their pros and cons, but other businesses usually decide to have people specialize in certain roles.

As you list out all of the necessary tasks, you realize that your friends clearly show a bias in which task they want to perform: one friend is rather bold and doesn’t mind taking to the streets to hand out flyers, one friend is really sociable and decides to handle customer service, and another friend is very exploratory and likes leaving the office to deliver orders around town. It strikes you that these people seem not only more eager to do these jobs, but also more likely to excel in their job due to their innate characteristics.

Luckily, you seem to have hired a diverse group of individuals and every person fits well into their role based on their personality. Even better, no one was trying to compete for jobs that had already been filled by the optimal number of people. Although no one was particularly interested in making the jewelry, you decide to keep performing this job yourself since you’ve gotten good at it through learning and experience. For the same reasons, everyone else gets better at their jobs over time and you notice, for example, that the bold people handing out flyers for you have become even bolder with every successful outing.

A few months pass and your business is doing great, especially compared to the other Etsy shops selling similar products to you. You decide to chat with some of the other shop owners and pick out a few key details about their business that’s limiting their success. Obviously, the one shop owner that is still working alone isn’t keeping up with everybody else; however, you also notice that a business with the same number of employees as you is also struggling. You talk to the owner more and you find out that they don’t have anybody on the street advertising, which seems to help out your business a whole lot. Apparently, all of their employees are very shy and just want to send out a few ads online, which isn’t as effective. What’s more, these shy individuals also aren’t very sociable so they have trouble handling disgruntled customers. As a result, your business continues to survive and thrive in competition with these other businesses and you get to open up two new shops while their empires crumble!  

This story doesn’t seem that crazy; every piece of it is well within the realm of possibility (but good luck getting that jewelry to catch on). But what if you were a spider? Does it seem plausible now?

Spiders certainly aren’t selling jewelry.  But they, along with many other animal species, go through similar experiences as you did and have to make similar decisions, if not in their lifetime, in their species’ evolution. Remember how you decided to take your one-man show and turn it into a group effort to increase your productivity and output? Many species of animals have evolved group-living as a way to increase productivity in spite of the challenges of surviving and reproducing in the wild.

There are many tasks that must be carried out in a group of animals, and when animals form groups, we see them divide up the labor. So these social species then face the same dilemma that you did: who does what? A few species simply divide tasks up by age or morphology of the group members. For example, young honey bees tend to take care of the eggs and brood in a colony, while older individuals forage and scout for new nest sites (Oster & Wilson 1978; Seeley 1982). In ants, the larger, “soldier” individuals defend the nest while the smaller, “nonsoldiers” tend to the brooding and the foraging requirements of the colony (Oster & Wilson 1978; Shingleton & Foster 2001). This age and morphological division of labor would be like you having all your younger friends handle the social media advertisement, or having your bigger, stronger friends lifting the heavy boxes of inventory. But many more species don’t divide up their tasks like this. So how do they do it?

Well, it may not be so different from the way your friends decided what jobs to do. More and more studies are finding that animals have personalities (Sih et al. 2004; Sih et al. 2012). In fact, even sea anemones, snails, and fruit flies have personalities (Hensley et al. 2012; Seaman & Briffa 2015; Kain et al. 2012)! Some animals are consistently bolder, more sociable, more exploratory, or more active than their groupmates.

Interestingly, recent studies have found that animals in a social group may be splitting up tasks based on their personalities. For example, bolder, more aggressive ants of the genus Myrmica patrol and guard the ant colony from invaders, while shyer, more sociable ants “babysit” pupae or find food for the colony (Chapman et al. 2011). It is intuitive that these “tough guy” ants are predisposed to fill this guard role as it aligns with their personality, and they are likely more proficient at this task than a reserved ant would be.

By filling different roles in their group, animals reduce competition with their groupmates through a process called “social niche specialization” (Bergmüller & Taborsky et al. 2010). Because  less fighting occurs between individuals of different social roles, roles become more and more different from each other. You saw this positive feedback loop with your bold friends who became bolder after handing out flyers all day. As a result of this phenomenon, if very similar animals are put into a group together, their personalities become drastically different from each other over time. By refining their personality and a job associated with it, animals become increasingly more skilled at the job they perform. Long story short: animals choose jobs because of their personalities, and their job makes their personality even stronger, which then makes them get better at their job, which then makes their personality even stronger, which then… whew, you see where this is going.

As you found with your business, the diversity of animal groups is essential to their performance. Several exciting studies have found group diversity of personality to be strongly correlated with group success (e.g. Pruitt & Reichert 2011; Modlmeier et al. 2012; Aplin et al. 2014) . This is predicted by “social heterosis,” which suggests that different personalities should complement each other in a group (Nonacs & Kapheim 2007). As you learned from the other shop owners, lack of group diversity can be catastrophic. As a result, mechanisms have evolved to maintain personality diversity in animal groups (Bergmüller & Taborsky 2010). Remember social niche specialization (Bergmüller & Taborsky 2010)? That’s a perfect example of one of these mechanisms. The final outcome is a group composed of diverse personalities dividing up the labor to improve efficiency and productivity. Adam Smith would be so proud!

Good luck with your jewelry aspirations!

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Authors:

Adrian Perez is a second year student in the ABGG. He studies honey bee division of labor.

Carter Loftus is a second year student in the ABGG. He studies inter-individual behavioral variation and its implications for group dynamics in wild olive baboons with Dr. Meg Crofoot.

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Literature Cited

Bergmüller, R., & Taborsky, M. (2010). Animal personality due to social niche specialisation. Trends in Ecology & Evolution, 25(9), 504-511.

Chapman, B. B., Thain, H., Coughlin, J., & Hughes, W. O. (2011). Behavioural syndromes at multiple scales in Myrmica ants. Animal Behaviour, 82(2), 391-397.

Hensley, N. M., Cook, T. C., Lang, M., Petelle, M. B., & Blumstein, D. T. (2012). Personality and habitat segregation in giant sea anemones (Condylactis gigantea). Journal of Experimental Marine Biology and Ecology, 426, 1-4.

Kain, J. S., Stokes, C., & de Bivort, B. L. (2012). Phototactic personality in fruit flies and its suppression by serotonin and white. Proceedings of the National Academy of Sciences, 109(48), 19834-19839.

Modlmeier, A. P., Liebmann, J. E., & Foitzik, S. (2012). Diverse societies are more productive: a lesson from ants. Proceedings of the Royal Society of London B: Biological Sciences, rspb20112376.

Nonacs, P., & Kapheim, K. M. (2007). Social heterosis and the maintenance of genetic diversity. Journal of evolutionary biology, 20(6), 2253-2265.

Pruitt J. N. & Reichart (2011). How within-group behavioural variation and task efficiency enhance fitness in a social group. Proc Biol Sci, 278, 1209-1215.

Sih, A., Bell, A., & Johnson, J. C. (2004). Behavioral syndromes: an ecological and evolutionary overview. Trends in ecology & evolution, 19(7), 372-378.

Sih, A., Cote, J., Evans, M., Fogarty, S., & Pruitt, J. (2012). Ecological implications of behavioural syndromes. Ecology letters, 15(3), 278-289.

Seaman, B., & Briffa, M. (2015). Parasites and personality in periwinkles (Littorina littorea): infection status is associated with mean-level boldness but not repeatability. Behavioural processes, 115, 132-134.