This week’s New Scientist includes a short piece from me about conformist rats.
Until now, only humans and chimps were known to succumb to peer pressure, to the extent that we often ignore our own experiences based on the preferences of others. But a new study in brown rats shows that these rodents are similarly prone to following the Joneses. They can even be persuaded to choose a piece of food that they know makes them sick if they smell it on the breath of a ‘demonstrator’ rat.
Bennett Galef and Elaine Whiskin at McMaster University in Hamilton, Ontaria, Canada, trained rats to avoid cinnamon-flavoured food pellets by injecting them with a nausea-inducing chemical (lithium chloride) after their meals. When given a choice between pellets flavoured with cocoa or cinnamon, they only went for the cinnamon ones about 5% of the time.
But after spending time in the company of other rats that had just eaten cinnamon themselves, they regained their liking for it and chose cinnamon pellets about a third of the time. In contrast, rats that were left alone still had a strong aversion.
The rats didn’t get to see the demonstrators actually eating any pellets so their change in behaviour was most likely motivated by the leftover scent of cinnamon on the tutors’ breath or fur. Residual odours explain how the rats conform but not why, and that’s the big remaining question. Why should social learning override individual experience so completely? Why would a rat, or for that matter a chimp or a human, cast aside what it knows from its own experience and adopt a potentially inferior strategy just because someone else is doing it?
Reference: GALEF, B., WHISKIN, E. (2008). Conformity in Norway rats?. Animal Behaviour DOI: 10.1016/j.anbehav.2007.11.012
Image: Rat by Reg McKenna
Related Topics
Go Further
Animals
- This ‘saber-toothed’ salmon wasn’t quite what we thoughtThis ‘saber-toothed’ salmon wasn’t quite what we thought
- Why this rhino-zebra friendship makes perfect senseWhy this rhino-zebra friendship makes perfect sense
- When did bioluminescence evolve? It’s older than we thought.When did bioluminescence evolve? It’s older than we thought.
- Soy, skim … spider. Are any of these technically milk?Soy, skim … spider. Are any of these technically milk?
- This pristine piece of the Amazon shows nature’s resilienceThis pristine piece of the Amazon shows nature’s resilience
Environment
- This pristine piece of the Amazon shows nature’s resilienceThis pristine piece of the Amazon shows nature’s resilience
- Listen to 30 years of climate change transformed into haunting musicListen to 30 years of climate change transformed into haunting music
- This ancient society tried to stop El Niño—with child sacrificeThis ancient society tried to stop El Niño—with child sacrifice
- U.S. plans to clean its drinking water. What does that mean?U.S. plans to clean its drinking water. What does that mean?
History & Culture
- Séances at the White House? Why these first ladies turned to the occultSéances at the White House? Why these first ladies turned to the occult
- Gambling is everywhere now. When is that a problem?Gambling is everywhere now. When is that a problem?
- Beauty is pain—at least it was in 17th-century SpainBeauty is pain—at least it was in 17th-century Spain
- The real spies who inspired ‘The Ministry of Ungentlemanly Warfare’The real spies who inspired ‘The Ministry of Ungentlemanly Warfare’
- Heard of Zoroastrianism? The religion still has fervent followersHeard of Zoroastrianism? The religion still has fervent followers
Science
- Here's how astronomers found one of the rarest phenomenons in spaceHere's how astronomers found one of the rarest phenomenons in space
- Not an extrovert or introvert? There’s a word for that.Not an extrovert or introvert? There’s a word for that.
- NASA has a plan to clean up space junk—but is going green enough?NASA has a plan to clean up space junk—but is going green enough?
- Soy, skim … spider. Are any of these technically milk?Soy, skim … spider. Are any of these technically milk?
- Can aspirin help protect against colorectal cancers?Can aspirin help protect against colorectal cancers?
Travel
- What it's like to hike the Camino del Mayab in MexicoWhat it's like to hike the Camino del Mayab in Mexico
- Follow in the footsteps of Robin Hood in Sherwood ForestFollow in the footsteps of Robin Hood in Sherwood Forest
- This chef is taking Indian cuisine in a bold new directionThis chef is taking Indian cuisine in a bold new direction
- On the path of Latin America's greatest wildlife migrationOn the path of Latin America's greatest wildlife migration
- Everything you need to know about Everglades National ParkEverything you need to know about Everglades National Park