Female Choice Key to Evolutionary Shift to Modern Family

It is a question that has puzzled evolutionary biologists for years: Why did we stop being promiscuous and decide to settle down to start families?

Sergey Gavrilets, professor of ecology and evolutionary biology at the University of Tennessee, Knoxville, may have found the answer, and it lies in the power of female choice. The study reveals how females chose their mates played a critical role in human evolution by leading to monogamous relationships, which laid the foundation for the institution of the modern family.

Using mathematical modeling, the associate director for scientific activities at the National Institute for Mathematical and Biological Synthesis (NIMBioS) at UT has discovered that the transformation may have occurred when early-hominid females started choosing males who were good providers.

Gavrilets' findings are published in the Proceedings of the National Academy of Sciences.

The "sexual revolution" entailed males first competing with other males for dominance, as a way to get matings. However, low-ranked males—and eventually all males except those with the highest societal stature—began supplying females with provisions in what is called "food-for-mating" to get a leg up on the competition. Females showed preference for the "provisioning" males, leading males' energy to be spent on providing for females and females becoming increasingly faithful. This spurred self-domestication and the modern family as we know it today.

"This change has confounded scientists for a long time because many species would be much better off evolutionarily if the effort spent on males competing for mates was redirected towards increasing female fertility or survivorship of their offspring," said Gavrilets.

The study demonstrates mathematically that the most commonly proposed theories for the transition to human pair bonding—or coupling—are not biologically feasible.

However, the study advances a new model showing that the transition to pair-bonding can occur when female choice and faithfulness, among other factors, are included. The result is an increased emphasis on males provisioning females over male competition for mating.

"The study reveals that female choice played a crucial role in human evolution," said Gavrilets.

According to Gavrilets, the transition to coupling has opened the path to intensified male parental investment, which was a breakthrough adaptation with multiple anatomical, behavioral and physiological consequences for early hominids and for all of their descendants. It shifted the dynamic away from males competing with each other for sex to males competing with each other to see who is a better provider to get better mates.

"Pair bonding laid the foundation for a later emergence of the institution of the modern family," said Gavrilets.

Source: University of Tennessee [May 30, 2012]

Read more »

'Losing yourself' in a fictional character can affect your real life

When you "lose yourself" inside the world of a fictional character while reading a story, you may actually end up changing your own behavior and thoughts to match that of the character, a new study suggests.

Researchers at Ohio State University examined what happened to people who, while reading a fictional story, found themselves feeling the emotions, thoughts, beliefs and internal responses of one of the characters as if they were their own - a phenomenon the researchers call "experience-taking."

They found that, in the right situations, experience-taking may lead to real changes, if only temporary, in the lives of readers.

In one experiment, for example, the researchers found that people who strongly identified with a fictional character who overcame obstacles to vote were significantly more likely to vote in a real election several days later.

"Experience-taking can be a powerful way to change our behavior and thoughts in meaningful and beneficial ways," said Lisa Libby, co-author of the study and assistant professor of psychology at Ohio State University.

There are many ways experience-taking can affect readers.

In another experiment, people who went through this experience-taking process while reading about a character who was revealed to be of a different race or sexual orientation showed more favorable attitudes toward the other group and were less likely to stereotype.

"Experience-taking changes us by allowing us to merge our own lives with those of the characters we read about, which can lead to good outcomes," said Geoff Kaufman, who led the study as a graduate student at Ohio State. He is now a postdoctoral researcher at the Tiltfactor Laboratory at Dartmouth College.

Their findings appear online in the Journal of Personality and Social Psychology and will be published in a future print edition.

Experience-taking doesn't happen all the time. It only occurs when people are able, in a sense, to forget about themselves and their own self-concept and self-identity while reading, Kaufman said. In one experiment, for example, the researchers found that most college students were unable to undergo experience-taking if they were reading in a cubicle with a mirror.

"The more you're reminded of your own personal identity, the less likely you'll be able to take on a character's identity," Kaufman said.

"You have to be able to take yourself out of the picture, and really lose yourself in the book in order to have this authentic experience of taking on a character's identity."

In the voting study, 82 undergraduates who were registered and eligible to vote were assigned to read one of four versions of a short story about a student enduring several obstacles on the morning of Election Day (such as car problems, rain, long lines) before ultimately entering the booth to cast a vote. This experiment took place several days before the 2008 November presidential election.

Some versions were written in first person ("I entered the voting booth) while some were written in third person ("Paul entered the voting booth"). In addition, some versions featured a student who attended the same university as the participants, while in other versions, the protagonist in the story attended a different university.

After reading the story, the participants completed a questionnaire that measured their level of experience-taking - how much they adopted the perspective of the character in the story. For example, they were asked to rate how much they agreed with statements like "I found myself feeling what the character in the story was feeling" and "I felt I could get inside the character's head."

The results showed that participants who read a story told in first-person, about a student at their own university, had the highest level of experience-taking. And a full 65 percent of these participants reported they voted on Election Day, when they were asked later.

In comparison, only 29 percent of the participants voted if they read the first-person story about a student from a different university.

"When you share a group membership with a character from a story told in first-person voice, you're much more likely to feel like you're experiencing his or her life events," Libby said. "And when you undergo this experience-taking, it can affect your behavior for days afterwards."

While people are more likely to lose themselves in a character who is similar to themselves, what happens if they don't learn that a character is not similar until later in a story?

In one experiment, 70 male, heterosexual college students read a story about a day in the life of another student. There were three versions - one in which the character was revealed to be gay early in the story, one in which the student was identified as gay late in the story, and one in which the character was heterosexual.

Results showed that the students who read the story where the character was identified as gay late in the narrative reported higher levels of experience-taking than did those who read the story where the character's homosexuality was announced early.

"If participants knew early on that the character was not like them - that he was gay - that prevented them from really experience-taking," Libby said.

"But if they learned late about the character's homosexuality, they were just as likely to lose themselves in the character as were the people who read about a heterosexual student."

Even more importantly, the version of the story participants read affected how they thought about gays.

Those who read the gay-late narrative reported significantly more favorable attitudes toward homosexuals after reading the story than did readers of both the gay-early narrative and the heterosexual narrative.

Those who read the gay-late narrative also relied less on stereotypes of homosexuals - they rated the gay character as less feminine and less emotional than did the readers of the gay-early story.

"If people identified with the character before they knew he was gay, if they went through experience-taking, they had more positive views - the readers accepted that this character was like them," Kaufman said.

Similar results were found in a story where white students read about a black student, who was identified as black early or late in the story.

Libby said experience-taking is different from perspective-taking, where people try to understand what another person is going though in a particular situation - but without losing sight of their own identity.

"Experience-taking is much more immersive - you've replaced yourself with the other," she said.

The key is that experience-taking is spontaneous - you don't have to direct people to do it, but it happens naturally under the right circumstance.

"Experience-taking can be very powerful because people don't even realize it is happening to them. It is an unconscious process," Libby said.

Author: Jeff Grabmeier | Source: Ohio State University [May 07, 2012]

Read more »