We’re all in this together: what spiders can teach us about teamwork

I took a career test in high school that was supposed to tell me my ideal career based on my personality. I’m not sure which boxes I checked, but my results indicated that I should either be a “box-packer” or a taxi driver. While I hope that I will have a career that relates more closely to what I have studied in college, I can see why my personality might suit me for those roles. It’s easy to imagine that somebody’s personality could be a good indicator of the kinds of jobs they might be good at: a very patient person will be a better teacher, a detail-oriented person will be a good copy editor, and a charismatic person will do well in sales.  There are tons of services and quizzes online that will even help you to do that!

A vital part of human society and civilization is the division of labor; we all do different things, and contribute differently to society. What we do is, at least in part, determined by who we are as people and what we’re like.

While the animal world may be lacking in patient teachers, meticulous copy editors, and gregarious salespeople, some of the same types of divisions occur. The Merriam-Webster English Dictionary defines personality (for people) as:

the set of emotional qualities, ways of behaving, etc., that makes a person different from other people

In animal behavior, on the other hand, personality is slightly more broadly described (as discussed by Gosling in 2001). Essentially, in both the human and the animal world, personalities make individuals stick out as different from others, when they may be outwardly similar. Animals in many taxa have personalities, and it has been found that animal populations in which there are varied personalities do better than populations with all the same personality. For example, rock ants have been shown to have more productive colonies when there are members with different levels of aggression (Modlmeier, 2011). Why do personalities exist at all? Why don’t animal populations just evolve the “best personality” and get rid of inferior ones? Studying these questions, and understanding how different personalities benefit populations and individuals, brings up many interesting avenues of research.

[1] Spiders are just like us!

Many of us might not get past adjectives like “terrifying” or “gross” when describing spiders – but if we look past the fear-factor, these arthropods are complex, fascinating, and even have personalities! Spider personalities are probably somewhat more limited than human personalities (at least in the current understanding), but they still provide the basis for research on animal personality.

In the tangle web spider species Anelosimus studiosus, female spiders are described as either docile or aggressive. How do we know which is which? Well, the aggressive ones wouldn’t be much fun at a party- to identify the aggressive females, they measured how far away other spiders sat when they were forced into a small space together (since aggressive females scare off everyone else). We also know that colonies with both personality types do better than all aggressive or all docile groups (this goes for not just spiders, but all sorts of animals). This big news in itself, and it begs the question – why do both of these personality types stick around?

[2] A lone Anelosimus studiosus hanging out in her web

Researchers in Georgia and Pittsburgh wanted to look even further into the personality differences in the spider. Do mixed-personality colonies do better simply because docile spiders ease the tension between their aggressive friends? Or do the different personality types provide other unique benefits to the colony? This species is sometimes solitary, but is often found in colonies of around 5 individuals. So we’ve got a little spider village, and in the village someone has to provide the food, someone has to take care of the babies, someone has to repair and build the home, and someone has to defend. How do the various personalities present in the colony affect who does what?

The researchers established colonies of all-docile, all-aggressive, and mixed personality spiders, and then watched them to see what they do. They kept track of who took care of the brood, they damaged the web and watched who fixed it, they placed threatening species nearby and watched who reacted aggressively to it, and to see who fulfilled the prey-capturing role, they vibrated a piece of cloth (With a vibrator. Yes, that kind of vibrator) and watched who came to check out the new potential food source.       
                   

It turns out that when the colonies have aggressive and docile members, the docile ones do more brood care, and the aggressive ones are more likely to spend their time trying to capture prey, fix the web, or defend the colony. In fact, aggressive individuals will spend the same amount of time doing these tasks whether or not there are docile members in the colony. Docile spiders, though, will spend their time differently depending on if there are aggressive colony mates; they spend more of their time caring for the brood if they have aggressive colony-mates which will spend more time doing the other tasks no matter what. The degree to which each job is accomplished in the colony, therefore, depends on the types of personalities of the members. An all-aggressive colony will have less cared-for young than an all-docile group, while an all-docile colony will have less response to prey than a mixed group or an all-aggressive group. The mixed groups will be better off over all than both types of single-personality groups.

[2] Figure from the article. Here we see that the left two clusters of bars are just about the same- showing that aggressive spiders do pretty much the same jobs in colonies of all aggressive spiders and in mixed colonies. Next, we see that docile spiders in mixed colonies perform mostly  brood care, which differs from  the last cluster showing docile spiders in all docile-colonies performing less brood care and more of the other tasks.

Let’s take this back to people. Some people like to be builders, hunters, and defenders. They will keep building, hunting, and defending the same amount, even if that means no one is taking care of the children. Then there are some people who are more flexible; if nobody else is building, hunting, and defending, they will let childcare fall by the wayside a bit to get those jobs done. But if other people take those jobs, they will focus much more time on childcare than anything else. Sounds like the flexible people (or the docile spiders) would be pretty helpful to have around in a mixed group, though when they’re on their own, they simply don’t do as much defending, hunting, or repairing. The docile and aggressive people will both benefit from having the others around, since they can each focus more on the jobs they are best at.

Well, why does this matter? This study unites the research done on animal personalities and on how animals work together in groups, and shows us an important way that division of labor could impact why different personalities appear.  Humans in groups work a lot like this too, in that project teams or other collaborative groups are most successful when the members have a variety of ways of thinking. This could relate to the different personalities of the members (not everyone can be a leader or a follower for example), or to differences in past experience, skills, or personal qualities. Businesses and institutions have figured out what spiders knew already…. Project teams will get work done best when members of the team bring different personalities and skills to the table.

[4] These musical high schoolers figured out something that our the tangle web spiders have known for a long time…

“Everyone is special in their own way
We make each other strong (we make each other strong)
We’re not the same 
We’re different in a good way
Together's where we belong”

Research Article:

Holbrook, C. Tate, Colin M. Wright, and Jonathan N. Pruitt. “Individual Differences in Personality and Behavioural Plasticity Facilitate Division of Labour in Social Spider Colonies.” Animal Behaviour 97 (November 2014): 177–83. doi:10.1016/j.anbehav.2014.09.015.Modlmeier, A. P., & Foitzik, S. (2011). Productivity increases with variation in aggression among group members in Temnothorax ants. Behavioral Ecology, 22, 1026e1032.
doi:10.1016/j.anbehav.2014.09.015 URL: http://www.sciencedirect.com/science/article/pii/S0003347214003510

Other citations:

Gosling, Samuel D. “From Mice to Men: What Can We Learn about Personality from Animal Research?” Psychological Bulletin 127, no. 1 (January 2001): 45–86. doi:10.1037/0033-2909.127.1.45.  

URL: http://web.b.ebscohost.com.ccl.idm.oclc.org/ehost/pdfviewer/pdfviewer?sid=9efc7e13-5da3-469f-b83d-37fddd92e202%40sessionmgr111&vid=8&hid=123

Modlmeier, Andreas P., and Susanne Foitzik. “Productivity Increases with Variation in Aggression among Group Members in Temnothorax Ants.” Behavioral Ecology, June 28, 2011, arr086. doi:10.1093/beheco/arr086.

URL: http://beheco.oxfordjournals.org/content/early/2011/06/28/beheco.arr086.full

Media credits:

“Personality.” Merriam-Webster, n.d.
[1] Photo by Dave Stokes:  https://www.flickr.com/photos/33909700@N02/11135438155/in/photolist-2YNZjk-gNwiuj-4iXGB7-4iTECH-8yuraC-hY12P2-pocTUz-9YZA9u-dMRton-8wJCfa-8gFPq1-c8wuVq-dii6te-565GVc-oFqWFz-adPDnR-fsyyoF-bMny8t-a5yXUo-4fus8W
[2] Photo by Sarah Zukoff:  https://www.flickr.com/photos/entogirl/7047046787/.
[3] Figure from Holbrook, C. Tate, Colin M. Wright, and Jonathan N. Pruitt. “Individual Differences in Personality and Behavioural Plasticity Facilitate Division of Labour in Social Spider Colonies.” Animal Behaviour 97 (November 2014): 177–83. doi:10.1016/j.anbehav.2014.09.015.
[4] Video by Disneymusic:  https://www.youtube.com/watch?v=BlRvE9dKWQc.