Less is more when choosing between groups of assorted items

Like humans, monkeys can make irrational decisions when making choices

2012-10-04

(Press-News.org) When making decisions about the value of an assortment of different objects, people approximate an average overall value, which though frequently useful can lead to apparently irrational decision-making. A new study published Oct 3 in PLOS ONE by Jerald Kralik and colleagues at Dartmouth College shows for the first time that non-human primates also make similar 'irrational' choices based on approximation.

In the study, researchers found that rhesus monkeys preferred a highly-valued food item (a fruit) alone to the identical item paired with a food of positive but lower value (fruit and a vegetable).

The researchers suggest that this behavior is similar to what has been seen in previous studies with humans, where participants rated a 24-piece dinnerware set more highly than one with the same 24 pieces, plus 16 more pieces of which nine were broken.

According to the authors, decision-making processes in humans and other primates have evolved towards reducing the complexity in choices between large groups of assorted items, which may result in such irrational choices.

"People often judge a group---of valuables, of foods, of other people---by its average rather than by the sum of its parts. Our study shows that monkeys appear to do the same thing, which suggests that both monkeys and people inherited a particular way of simplifying the world around us, making choices easier, sometimes at the expense of 'rationality'" says Kralik.

INFORMATION:

Citation: Kralik JD, Xu ER, Knight EJ, Khan SA, Levine WJ (2012) When Less Is More: Evolutionary Origins of the Affect Heuristic. PLoS ONE 7(10): e46240.doi:10.1371/journal.pone.0046240

Financial Disclosure: Grant NIMH 1 K22 MH071756-01 from the National Institute of Mental Health (NIMH), a component of the National Institutes of Health (NIH): http://www.nimh.nih.gov/index.shtml. Grant CM-5 P40 RR003640-20 from the National Center for Research Resources (NCRR), a component of the National Institutes of Health (NIH): http://www.ncats.nih.gov/. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing Interest Statement: The authors have declared that no competing interests exist.

[Attachments] See images for this press release:

ELSE PRESS RELEASES FROM THIS DATE:

Mollusc missing link revealed in 3-D

2012-10-04

Scientists have discovered a rare fossil called Kulindroplax, the missing link between two mollusc groups, which is revealed in a 3D computer model, in research published today in the journal Nature. The researchers have unearthed the worm-like partly shelled Kulindroplax, which they have modelled in a 3D computer animation. Kulindroplax lived in the sea during the Silurian Period, approximately 425 million years ago, when most life lived in the oceans and the first plants were beginning to grow on land. The team found the Kulindroplax fossil, the only one of its kind ...

Blocking tumor-induced inflammation impacts cancer development

2012-10-04

Researchers at the University of California, San Diego School of Medicine report the discovery of microbial–dependent mechanisms through which some cancers mount an inflammatory response that fuels their development and growth. The findings are published in the October 3, 2012 Advanced Online Edition of Nature. The association between chronic inflammation and tumor development has long been known from the early work of German pathologist Rudolph Virchow. Harvard University pathologist Harold Dvorak later compared tumors with "wounds that never heal," noting the similarities ...

Healthcare professionals as bad as patients at good respiratory inhaler technique

2012-10-04

Healthcare professionals are as bad as patients when it comes to knowing how to use inhalers prescribed for asthma and other respiratory conditions correctly, says an editorial in Drug and Therapeutics Bulletin (DTB). They therefore can't be relied on to teach patients how to use these devices correctly, says DTB. But as 45 million prescriptions for respiratory inhalers were dispensed in 2011 in England alone—at a cost of £900 million to the NHS—everyone needs to be more clued up on correct inhaler technique to make sure these drugs work well for patients and offer ...

Aspirin may temper brain power decline in elderly women at risk of heart disease

2012-10-04

Daily low dose aspirin could slow the decline in brain power among elderly women at high risk of heart disease, indicates observational research published in the online journal BMJ Open. The researchers base their findings on 681 women between the ages of 70 and 92, 601 of whom were at high risk of heart disease and stroke, defined as a 10% or greater risk on a validated risk scale (Framingham). All the women were subjected to a battery of tests to measure their physical health and intellectual capacity, including verbal fluency and memory speed, and dementia (mini ...

Ancient mollusk tells a contrary story

2012-10-04

New Haven, Conn. — A fossil unearthed in Great Britain may end a long-running debate about the mollusks, one of life's most diverse invertebrate groups: Which evolved first, shelled forms like clams and snails, or their shell-less, worm-like relatives? The small new fossil, found in marine rocks along the English-Welsh border, provides the best fossil evidence yet that the simpler worm-like mollusks evolved from their more anatomically complex shelled brethren, rather than the other way around. The discovery reinforces previous findings from molecular sequencing studies ...

Southern Hemisphere becoming drier

2012-10-04

A decline in April-May rainfall over south-east Australia is associated with a southward expansion of the subtropical dry-zone according to research published today in Scientific Reports, a primary research journal from the publishers of Nature. CSIRO scientists Wenju Cai, Tim Cowan and Marcus Thatcher explored why autumn rainfall has been in decline across south-eastern Australia since the 1970s, a period that included the devastating Millennium drought from 1997-2009. Previous research into what has been driving the decline in autumn rainfall across regions like southern ...

Black hole surprise in ancient star cluster

2012-10-04

Astronomers have made the unexpected discovery of two black holes inside an ancient cluster of stars in our galaxy, the Milky Way. The research, published today in the prestigious journal Nature, describes the detection of two black holes that are about 10 to 20 times heavier than our Sun in the globular cluster named M22. Black holes, so dense that even light can't escape them, are what is left when a massive star reaches the end of its life and collapses in on itself. Co-author Dr James Miller-Jones, from the Curtin University node of the International Centre for ...

Researchers identify dozens of new de novo genetic mutations in schizophrenia

2012-10-04

New York, NY (October 3, 2012) — Columbia University Medical Center (CUMC) researchers have identified dozens of new spontaneous genetic mutations that play a significant role in the development of schizophrenia, adding to the growing list of genetic variants that can contribute to the disease. The study, the largest and most comprehensive of its kind, was published today in the online edition of the journal Nature Genetics. Although schizophrenia typically onsets during adolescence and early adulthood, many of the mutations were found to affect genes with higher expression ...

UT Dallas research shows graphene nanopores can be controlled

2012-10-04

Engineers at The University of Texas at Dallas have used advanced techniques to make the material graphene small enough to read DNA. Shrinking the size of a graphene pore to less than one nanometer – small enough to thread a DNA strand – opens the possibility of using graphene as a low-cost tool to sequence DNA. "Sequencing DNA at a very cheap cost would enable scientists and doctors to better predict and diagnose disease, and also tailor a drug to an individual's genetic code," said Dr. Moon Kim, professor of materials science and engineering. He was senior author ...

Tomb of Maya queen K'abel discovered in Guatemala

2012-10-04

Archaeologists in Guatemala have discovered the tomb of Lady K'abel, a seventh-century Maya Holy Snake Lord considered one of the great queens of Classic Maya civilization. The tomb was discovered during excavations of the royal Maya city of El Perú-Waka' in northwestern Petén, Guatemala, by a team of archaeologists led by Washington University in St. Louis' David Freidel, co-director of the expedition. Along with David Freidel, professor of anthropology at WUSTL, the project is co-directed by Juan Carlos Pérez, former vice minister of culture for cultural heritage of ...

International survey finds that support for climate interventions is tied to being hopeful and worried about climate change

NRG Oncology trial supports radiotherapy alone following radical hysterectomy should remain the standard of care for early-stage, intermediate-risk cervical cancer

Less is more when choosing between groups of assorted items

ELSE PRESS RELEASES FROM THIS DATE:

LAST 30 PRESS RELEASES: