Ants more rational than humans

Jul 24, 2009
Ants are more rational collective decision makers than humans. Credit: Stephen Pratt/Arizona State University

In a study released online on July 22 in the journal Proceedings of the Royal Society: Biological Sciences, researchers at Arizona State University and Princeton University show that ants can accomplish a task more rationally than our - multimodal, egg-headed, tool-using, bipedal, opposing-thumbed - selves.

This is not the case of humans being "stupider" than . Humans and animals simply often make irrational choices when faced with very challenging decisions, note the study's architects Stephen Pratt and Susan Edwards.

"This paradoxical outcome is based on apparent constraint: most individual ants know of only a single option, and the colony's collective choice self-organizes from interactions among many poorly-informed ants," says Pratt, an assistant professor in the School of Life Sciences in ASU's College of Liberal Arts and Sciences.

The authors' insights arose from an examination of the process of nest selection in the ant, Temnothorax curvispinosus. These ant colonies live in small cavities, as small as an acorn, and are skillful in finding new places to roost. The challenge before the colony was to "choose" a nest, when offered two options with very similar advantages.

What the authors found is that in collective decision-making in ants, the lack of individual options translated into more accurate outcomes by minimizing the chances for individuals to make mistakes. A "wisdom of crowds" approach emerges, Pratt believes.

"Rationality in this case should be thought of as meaning that a decision-maker, who is trying to maximize something, should simply be consistent in its preferences." Pratt says. "For animals trying to maximize their fitness, for example, they should always rank options, whether these are food sources, mates, or nest sites, according to their fitness contribution."

"Which means that it would be irrational to prefer choice 'A' to 'B' on Tuesday and then to prefer 'B' to 'A' on Wednesday, if the fitness returns of the two options have not changed."

"Typically we think having many individual options, strategies and approaches are beneficial," Pratt adds, "but irrational errors are more likely to arise when individuals make direct comparisons among options."

Studies of how or why irrationality arises can give insight into cognitive mechanisms and constraints, as well as how collective decision making occurs. Insights such as Pratt's and Edward's could also translate into new approaches in the development of artificial intelligence.

"A key idea in collective robotics is that the individual robots can be relatively simple and unsophisticated, but you can still get a complex, intelligent result out of the whole group," says Pratt. "The ability to function without complex central control is really desirable in an artificial system and the idea that limitations at the individual level can actually help at the group level is potentially very useful." Pratt is a member of Heterogeneous Unmanned Networked Team (HUNT), a project funded by the Office of Naval Research (ONR) to enable to development of bio-inspired solutions to engineering problems.

What do these findings potentially say about understanding human social systems?

"It is hard to say. But it's at least worth entertaining the possibility that some strategic limitation on individual knowledge could improve the performance of a large and complex group that is trying to accomplish something collectively," Pratt says.

Source: Arizona State University (news : web)

Explore further: Orchid named after UC Riverside researcher

add to favorites email to friend print save as pdf

Related Stories

How house-hunting ants choose the best home

Apr 22, 2009

(PhysOrg.com) -- Direct comparison of alternatives isn’t always the best way to make a decision - at least if you’re an ant. House-hunting rock ants collectively manage to choose the best nest-site without ...

Insects inspire robotics research

Aug 21, 2006

Insects are proving invaluable for one researcher at the University of Alberta, who hopes robots can perform the same types of tasks that ants or bees do.

Ants on the brain

Feb 25, 2009

(PhysOrg.com) -- Colonies of social insects such as ants and bees could collectively make decisions using mechanisms similar to those used in primate brains, according to new research from the University of ...

Can an ant be employee of the month?

Nov 18, 2008

Ants specializing on one job such as snatching food from a picnic are no more efficient than "Jane-of-all-trade" ants, according to new research.

Recommended for you

Male monkey filmed caring for dying mate (w/ Video)

3 hours ago

(Phys.org) —The incident was captured by Dr Bruna Bezerra and colleagues in the Atlantic Forest in the Northeast of Brazil.  Dr Bezerra is a Research Associate at the University of Bristol and a Professor ...

Orchid named after UC Riverside researcher

21 hours ago

One day about eight years ago, Katia Silvera, a postdoctoral scholar at the University of California, Riverside, and her father were on a field trip in a mountainous area in central Panama when they stumbled ...

In sex-reversed cave insects, females have the penises

23 hours ago

Researchers reporting in the Cell Press journal Current Biology on April 17 have discovered little-known cave insects with rather novel sex lives. The Brazilian insects, which represent four distinct but re ...

Fear of the cuckoo mafia

23 hours ago

If a restaurant owner fails to pay the protection money demanded of him, he can expect his premises to be trashed. Warnings like these are seldom required, however, as fear of the consequences is enough to ...

User comments : 9

Adjust slider to filter visible comments by rank

Display comments: newest first

ormondotvos
5 / 5 (2) Jul 24, 2009
How Straussian the implicit concept here that depriving actors of information makes them better collectivist wise robots. Works for me. Not politically correct, though.
OregonWind
5 / 5 (2) Jul 24, 2009
'Ants more rational than humans"

I am not surprised. :)
Soylent
4.7 / 5 (3) Jul 24, 2009
You have to be very careful with the word rational.

It can be rational within a context to behave in a seemingly irrational way because of the message that sends to an opponent.
getgoa
1 / 5 (1) Jul 25, 2009
The ants are more rational than the ant is how the article should read in my opinion. What I understand from the article is that it would be more irrational to avoid the group to get more power independently of the groups knowledge.
ciantic
1 / 5 (1) Jul 25, 2009
"... the idea that limitations at the individual level can actually help at the group level is potentially very useful."

In other words, we are lucky that single Neuron is stupid.

What I mean that bunch of ants should be compared to single human, since Neuron kind of represents single ant.
Caliban
1 / 5 (1) Jul 25, 2009
Not a word as to how the "rational" decision to select one nesting site versus the other was arrived at, or at what level of ant heirarchy it was made, or for what putative reason(s). Therefore, it follows that ants behave more rationally?
nevermark
2.5 / 5 (2) Jul 25, 2009
At Apple different subgroups on a project are often unaware of what sibling teams are doing. Management holds back info, which lets them keep options open until the best solution emerges.

At Microsoft the opposite occurred for a long time. Engineers in small groups would often charge ahead of management direction. One of the factors in Windows out competing IBM's OS/2 was that engineers went ahead and solved problems management didn't think could or even should be solved, until they were handed the solution.

In both cases limited info made for greater flexibility, better solutions.

ArtflDgr
3 / 5 (2) Jul 27, 2009
rationality only works for slaves who are expendable. then the game is who can do best and lose the fewest workers, this is decidedly different than a mass of cooperative/competitive individuals.

their aim is to remove the middle, while complaining that this gap is getting wider. when this is done, you will have eternal slaves on the bottom reinforced by genetics as they adapt to their prisons, and the elite on the top. that dark age will continue till the poor get wealthy again to force kings to be beuracrats again.
Caliban
1 / 5 (1) Jul 27, 2009
Right on, Brother! Morlocks Unite!

More news stories

Researchers develop new model of cellular movement

(Phys.org) —Cell movement plays an important role in a host of biological functions from embryonic development to repairing wounded tissue. It also enables cancer cells to break free from their sites of ...

Scientists tether lionfish to Cayman reefs

Research done by U.S. scientists in the Cayman Islands suggests that native predators can be trained to gobble up invasive lionfish that colonize regional reefs and voraciously prey on juvenile marine creatures.