Nav: Home

Nature versus nurture

March 14, 2016

Scientists have long agreed that we humans are a complex combination of our inherited traits and the environments in which we are raised. How the scales tip in one direction or the other, however, is still the subject of much debate.

To better understand the nature versus nurture question, UC Santa Barbara psychologist John Protzko analyzed an existing study to determine whether and how environmental interventions impacted the intelligence levels of low birth weight children.

The key finding: Interventions did raise intelligence levels, but not permanently. When the interventions ended, their effects diminished over time in what psychologists describe as "the fadeout effect." The research is highlighted in the journal Intelligence.

"Certain environmental interventions can raise general intelligence," said Protzko, a postdoctoral scholar in the META (Memory, Emotion, Thought, Awareness) Lab in UCSB's Department of Psychological & Brain Sciences. "It's not just pushing scores around on a test; it's deep changes to underlying general intelligence. The fadeout effect, however, applies the same way." Scientists make a distinction between IQ scores, a quantitative measure of intelligence, and general intelligence, which reflects underlying cognitive abilities.

Protzko reviewed the results of the Infant Health and Development Program involving 985 children, all of whom experienced an intense and cognitively demanding environment during the first three years of their lives. Three main interventions had been employed to ameliorate the negative effects of being born at low birth weight.

At age 3, the children were given the Stanford-Binet Intelligence Scales as a baseline measure of their intelligence. At ages 5 and 8 -- at least two years after the interventions had ended -- they were again given intelligence tests.

The results showed that the interventions had raised the children's general intelligence at age 3. However, by age 5 the increases were no longer evident. According to Protzko, this demonstrates that the fadeout effect applies to general intelligence.

He also noted that this difference in intelligence at ages 3 and 5 underscored another issue: causality. One theory regarding the development of intelligence suggests that the trait can be correlated between two ages because there is a causal connection: Intelligence at one age causes intelligence at another age.

"However, my analysis starts to bring evidence to the idea that intelligence may not be the causal factor we suppose it to be from the correlation work -- at least not in children," Protzko explained. "It's unlikely that given an increase in intelligence, I would live my life any differently than I do right now. This work will have to be done in adults to really pull that apart, but I think that this analysis starts to bring evidence against that idea of causality."

This is the second of two papers Protzko has published on the fadeout effect. Both highlight the unidirectional reaction model, which suggests that intelligence can adapt to meet increased environmental demands but when those demands are no longer present, it returns to its previous level.

"Raising IQ is not an instance of raising test scores with no concomitant effects on the latent underlying intelligence," Protzko said. "While both IQ scores and general intelligence can be raised through targeted environmental interventions, any gains are not permanent and fade over time.

Nonetheless, he noted, his analysis doesn't indicate that interventions aimed at enhancing intellectual development are useless or doomed to fail. "I believe it is still a good thing to intervene and try to change the trajectory for these children," he said.
-end-


University of California - Santa Barbara

Related Intelligence Articles:

Artificial intelligence improves biomedical imaging
ETH researchers use artificial intelligence to improve quality of images recorded by a relatively new biomedical imaging method.
Uncovering hidden intelligence of collectives
Research team including scientists from Konstanz discovers that information processing in animal groups occurs not only in the brains of animals but also in their social network.
Evolution of learning is key to better artificial intelligence
Researchers at Michigan State University say that true, human-level intelligence remains a long way off, but their new paper published in The American Naturalist explores how computers could begin to evolve learning in the same way as natural organisms did -- with implications for many fields, including artificial intelligence.
The brain inspires a new type of artificial intelligence
Using advanced experiments on neuronal cultures and large scale simulations, scientists at Bar-Ilan University have demonstrated a new type of ultrafast artifical intelligence algorithms -- based on the very slow brain dynamics -- which outperform learning rates achieved to date by state-of-the-art learning algorithms.
Can videogames promote emotional intelligence in teenagers?
A new study has shown that videogames, when used as part of an emotional intelligence training program, can help teenagers evaluate, express, and manage their own emotions immediately after the training.
More Intelligence News and Intelligence Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Rethinking Anger
Anger is universal and complex: it can be quiet, festering, justified, vengeful, and destructive. This hour, TED speakers explore the many sides of anger, why we need it, and who's allowed to feel it. Guests include psychologists Ryan Martin and Russell Kolts, writer Soraya Chemaly, former talk radio host Lisa Fritsch, and business professor Dan Moshavi.
Now Playing: Science for the People

#537 Science Journalism, Hold the Hype
Everyone's seen a piece of science getting over-exaggerated in the media. Most people would be quick to blame journalists and big media for getting in wrong. In many cases, you'd be right. But there's other sources of hype in science journalism. and one of them can be found in the humble, and little-known press release. We're talking with Chris Chambers about doing science about science journalism, and where the hype creeps in. Related links: The association between exaggeration in health related science news and academic press releases: retrospective observational study Claims of causality in health news: a randomised trial This...