Management Insights, a regular feature of the journal, is a digest of important research in business, management, operations research, and management science. It appears in every issue of the monthly journal.

“Are Overconfident CEOs Born or Made? Evidence of Self-Attribution Bias from Frequent Acquirers” is by Matthew T. Billett and Yiming Qian of the University of Iowa.

Whether to engage in mergers and acquisitions is one of the most important decisions top managers make, the authors write. While many of the factors influencing these decisions may be based on objective financial metrics, there is increasing evidence that behavioral biases play an important role in managerial decision making. The authors explore one such bias—managerial overconfidence— and find evidence suggesting CEOs develop overconfidence through ‘self-attribution bias’ when making merger and acquisition decisions. Individuals subject to self-attribution bias overcredit their role in bringing about good outcomes and underestimate the role of luck.

Consistent with this, they find that CEOs appear to overly attribute their role in successful deals, leading to more deals even though these subsequent deals are value destructive.

They also find evidence that CEOs alter their stock holdings prior to deals in a pattern consistent with overconfidence in the outcome of these subsequent deals.

The authors advise that CEOs be particularly cautious and disciplined when engaging in acquisitions following prior success. Boards and other stakeholders should also ensure that any proposed deal is judged on its own merits and is not justified on the basis of prior CEO success in mergers and acquisitions, they say.

Professors Billett and Zian based their results on a sample of public acquisitions between 1985 and 2002. Over this period, U.S. public companies acquired $3.7 trillion worth of other U.S. public companies.

A team of Penn State researchers has shown for the first time that the entire class of non-magnetic materials, such as those used in some computer components, could have considerably more uses than scientists had thought. The findings are important because they reveal previously unknown information about the structure of these materials, expanding the number of properties that they potentially could have. A material's properties, such as electrical conductivity and mechanical strength, are what determine its usefulness. The research will be published in the journal Physical Review Letters.

A material's properties are determined by its structure, explained Venkatraman Gopalan, a researcher in Penn State's Center for Nanoscale Science, a professor of materials science and engineering, and the project's leader. "If I was out hiking and I found a rock that contained a quartz crystal, I could tell you what properties the crystal can and cannot have just based on what we call its symmetry--the number and arrangement of crystal planes it has. Symmetry results from the way the atoms are arranged in the quartz," he said. "It is an extremely powerful way of understanding our world."

The non-magnetic materials that Gopalan and his colleagues studied were thought to have one of the 32 different crystal symmetries--called point group symmetries--known to exist in nature. On the other hand, magnetic materials have 90 different point group symmetries because their atomic particles have magnetic spins, which can be imagined as tiny loops of current. "Motion is an extremely important aspect of magnetism," said Gopalan. "Magnetism develops in nature as soon as charged particles start moving or spinning."

Scientists long have believed that symmetry allows magnetic materials to have more properties than non-magnetic materials because flipping the direction of spin creates an additional symmetry. But Gopalan's team has shown that non-magnetic materials, theoretically, can have just as many properties as magnetic materials. According to Gopalan, some non-magnetic materials have groups of atoms that distort by twisting or rotating. This slight movement is equivalent to a tiny loop of current and is enough to give the material some additional properties that previously were thought to belong only to magnetic materials.

The researchers tested their theory experimentally using strontium titanate, which is a non-magnetic material. They cooled the material and found that its oxygen atoms responded by twisting into a tighter postion to save energy and space. "The oxygen atoms don't rotate all the way around like a loop of current does in magnetic materials, but theoretical analyses show that they do twist and, therefore, it is possible that these materials could have previously unknown properties," said Gopalan.

Next, the team investigated whether the twisting movement translated into the expression of additional properties. In particular, they predicted and tested for an optical property that they call roto second harmonic generation, which is analogous to a well-known property called magnetic second harmonic generation. Second harmonic generation is found, for example, in the crystals that are used in green laser pointers to convert infrared laser light into green laser light. The group found that the strontium titanate material does have a small amount of roto second harmonic generation.

"Nobody has thought of relating magnetic symmetries to a non-magnetic material like strontium titanate, but that's precisely what our paper does," said Gopalan. "We first did a theoretical analysis in which we applied the symmetry framework that traditionally is used to describe magnetic materials to this vast class of non-magnetic materials. Then we did a laboratory experiment with a particular non-magnetic material and we found that it has a property that previously was thought to belong only to magnetic materials. We suggest that it is possible for the entire class of non-magnetic materials to have more symmetries and more properties than previously have been thought possible."

The team's findings could lead to an explosion of research into new properties of non-magnetic materials and to possible applications of these properties. "These materials are used in hundreds of applications," said Peter Schiffer, associate vice president for research and a professor of physics at Penn State, "but this new work holds great promise for finding many more uses."

"The population was split into two groups, then one of the groups died out 45,000 years ago, long before the first humans began to appear in the region," said Stephan C. Schuster, associate professor of biochemistry and molecular biology at Penn State University and a leader of the research team. "This discovery is particularly interesting because it rules out human hunting as a contributing factor, leaving climate change and disease as the most probable causes of extinction." The discovery will be published later this week in the early online edition of the Proceedings of the National Academy of Sciences (PNAS).

The research marks the first time scientists have dissected the structure of an entire population of extinct mammal by using the complete mitochondrial genome -- all the DNA that makes up all the genes found in the mitochondria structures within cells. Data from this study will enable testing of the new hypothesis presented by the team, that there were two groups of woolly mammoth -- a concept that previously had not been recognized from studies of the fossil record.

The scientists analyzed the genes in hair obtained from individual woolly mammoths -- an extinct species of elephant adapted to living in the cold environment of the northern hemisphere. The bodies of these mammoths were found throughout a wide swathe of northern Siberia. Their dates of death span roughly 47,000 years, ranging from about 13,000 years ago to about 60,000 years ago.

Schuster and Webb Miller, professor of biology and computer science and engineering at Penn State, led the international research team, which includes Thomas Gilbert at the University of Copenhagen in Denmark and other scientists in Australia, Belgium, France, Italy, Russia, Spain, Sweden, the United Kingdom, and the United States. The team includes experts in the fields of genome evolution, ancient DNA, and mammoth paleontology, as well as curators from various natural-history museums.

Another important finding for understanding the extinction processes is that the individuals in each of the two woolly-mammoth groups were related very closely to one another. "This low genetic divergence is surprising because the woolly mammoth had an extraordinarily wide range: from Western Europe, to the Bering Strait in Siberia, to Northern America," Miller said. "The low genetic divergence of mammoth, which we discovered, may have degraded the biological fitness of these animals in a time of changing environments and other challenges."

Our study suggests a genetic divergence of the two woolly-mammoth groups more than 1-million years ago, which is one quarter the genetic distance that separates Indian and African elephants and woolly mammoths," Miller said. The research indicates that the diversity of the two woolly-mammoth populations was as low centuries ago as it is now in the very small populations of Asian elephants living in southern India. "The low genetic divergence of the elephants in southern Indian has been suggested as contributing to the problems of maintaining this group as a thriving population," Schuster said. Intriguingly, the mitochondrial genomes revealed by the researchers are several times more complete than those known for the modern Indian and African Elephants combined.

Whereas studies before this research had analyzed only short segments of the DNA of extinct species, this new study generated and compared 18 complete genomes of the extinct woolly mammoth using mitochondrial DNA, an important material for studying ancient genes. This achievement is based on an earlier discovery of the team led by Miller, Schuster, and co-author Thomas Gilbert, which was published last year and that revealed ancient DNA survives much better in hair than in any other tissue investigated so far. This discovery makes hair, when it is available, a more powerful and efficient source of DNA for studying the genome sequences of extinct animals. Moreover, mammoth hair is found in copious quantities in cold environments and it is not regarded as fossil material of enormous value like bone or muscle, which also carries anatomical information.

"We also discovered that the DNA in hair shafts is remarkably enriched for mitochondrial DNA, the special type of DNA frequently used to measure the genetic diversity of a population," Miller said. The team's earlier study also showed that hair is superior for use in molecular-genetic analysis because it is much easier than bone to decontaminate. Not only is hair easily cleaned of external contamination such as bacteria and fungi, its structure also protects it from degradation, preventing internal penetration by microorganisms in the environment.

An important aspect of the new study is that the hair samples it used had been stored in various museums for many years before being analyzed by the researchers, yet the scientists were able to obtain lots of useful DNA from them. "One of our samples originates from the famous Adams mammoth, which was found in 1799 and has been stored at room temperatures for the last 200 years," Schuster said. This research technique opens the door for future projects to target interesting specimens that were collected a long time ago and are no longer available from modern species, the scientists said. Even the molecular analysis of entire collections seems now possible, an effort that the team calls "Museomics."

"We plan to continue using our techniques to untangle the secrets of populations that lived long ago and to learn what it might have taken for them to survive," Schuster said. "Many of us also have a personal interest in learning as much as we can about how any species of large mammal can go extinct."

Greg Smutzer, director of the Laboratory of Gustatory Psychophysics in the Biology Department of Temple's College of Science and Technology (http://www.temple.edu/biology), has created taste strips similar to breath-freshening strips, but these edible strips contain one of the five basic tastes that are detected by humans — sweet, sour, salty, bitter and monosodium glutamate, which is also known as umami taste.

This research, "A Test for Measuring Gustatory Function," has been published in the June 2 online "Ahead of Print" edition of The Laryngoscope (http://www.thelaryngoscope.com), the journal of the American Laryngological, Rhinological and Otological Society.

The idea was born when a lab equipment repairman who was a friend of Smutzer's stopped by the laboratory more than four years ago and offered him one of the new breath-freshening strips.

He said, "You have to try one of these," Smutzer recalled. "I had never seen the strips before. But as soon as he showed them to me, one of my first thoughts was, this technology would be ideal for a taste test because it is so simple to use."

Smutzer starts by using a combination of two polymers, pullulan and Methocel. His strips are created by dissolving the polymers — in the form of powders — in warm water and then allowing the solution to cool to room temperature. Added into the solution is a small amount of a taste stimulus that will give each strip the desired taste: sodium chloride for salty, sucrose for sweet, ascorbic acid for sour, quinine for bitter, and monosodium glutamate for umami taste.

Once the solution is cool, it is then poured onto Teflon-coated pans and allowed to dry five to six hours in order to produce a clear, thin film. When dry, the films are carefully removed, and cut into one-inch-square strips.

He said that pullulan, a major ingredient of the Listerine breath strips, is tasteless and dissolves within seconds in the mouth. Methocel is added in small amounts to increase the tensile strength of the pullulan films.

The development of the taste strips solves a problem for researchers. According to Smutzer, no standardized method for rapidly measuring taste function in humans is currently available, and taste norms for the human population as a function of age and sex have yet to be determined.

"What is typically done in the lab is a 'sip and spit' test, where a liquid solution is prepared that contains dissolved tastant," Smutzer explained. "You then place a small amount of the solution, maybe half an ounce, into a small cup for the test subject to place into their mouth, swish around and then spit it out."

But this type of test is difficult to administer outside the lab because the solutions have a very short shelf life and are not very portable, he said. Another big problem with the liquid test is that it cannot be effectively used to examine selected regions of the tongue, such as just one side, the front or the back of the tongue.

"It is very difficult to do regional testing with the liquid test because it is tough to concentrate liquid in just one area of the mouth," said Smutzer, who is hoping to commercialize the taste strips. "We can alter the size or thickness of these strips, place them on a desired area of the tongue and allow saliva to dissolve them without causing the tastant to spread over the surface of the tongue."

Since different parts of the tongue may respond to different tastes, or may respond more or less strongly to the same taste stimulus. Smutzer said his taste strips could be used to develop detailed taste maps of the tongue surface, a project he plans to examine in the future.

Another major advantage of this technology, according to Smutzer, is that the strips can measure thresholds for tastants at levels that are from 10 to 100 times lower when compared to a standard "sip and spit" test. These lower threshold values for sweet, sour, salty, bitter or umami taste could be useful for examining taste disturbances in clinical populations where such disturbances have not been previously identified.

Smutzer added that his strips, which are stored at room temperature and have been used up to six months after being produced, could also be beneficial to the pharmaceutical industry, since certain medications can create temporary taste disturbances. He said that subjects could be tested with taste strips during clinical trials to determine whether new drugs or therapies interfere with taste function.

The popularity of golf carts has skyrocketed in recent years, and unfortunately so has the number of golf cart-related injuries. In fact, a new study conducted by researchers in the Center for Injury Research and Policy of The Research Institute at Nationwide Children's Hospital found that the number of golf cart-related injuries rose 132 percent during the 17-year study period.

According to the study, published in the July issue of the American Journal of Preventive Medicine (available online), there were an estimated 148,000 golf cart-related injuries between 1990 and 2006, ranging from an estimated 5,770 cases in 1990 to approximately 13,411 cases in 2006.

As golf carts have become faster and more powerful, they are no longer limited to use on the golf course. In addition to their traditional role, golf carts are now routinely being used at sporting events, hospitals, airports, national parks, college campuses, business parks and military bases. While the study found that the majority of golf cart-related injuries (more than 70 percent) took place at sports or recreational facilities, individuals injured in carts on the street had an increased risk of concussions and were more likely to require hospitalization than individuals injured in other locations.

While the most common cause of injury for all ages was falling or jumping from the cart, study co-author Gary Smith, MD, DrPH, director of the Center for Injury Research and Policy at Nationwide Children's Hospital, and an associate professor of pediatrics at The Ohio State University College of Medicine explained, "Children are even more likely than adults to fall from the golf cart, and these falls are associated with higher rates of head and neck injuries and hospitalizations. Greater efforts are needed to prevent these injuries."

More than 30 percent of golf cart-related injuries involved children under the age of 16.

"Because golf carts are not designed for children and the majority offer no child safety features, we recommend that children under the age of 6 years not be transported in golf carts and that drivers be at least 16 years old to operate the vehicle," said study co-author Tracy Mehan, MA, CPST, research associate in the Center for Injury Research and Policy at Nationwide Children's.

The study recommends that more effective safety features, such as improved passenger restraints and four-wheel brakes, in combination with training programs and safety policies would reduce the overall number of golf cart-related injuries.

"Following a few safety precautions, such as driving at a reasonable speed, wearing seat belts when they are available, braking slowly and considering the terrain and weather conditions can reduce the potential for injuries," said Mehan.

Facilities where golf carts are used can also help prevent golf cart-related injuries by establishing safety policies, requiring driver's licenses and operator training and considering safety when designing the pathways golf carts will be using.

Apparently not, according to a new study that measured individuals' heart recovery rate from minor stress when exposed to a natural scene through a window, the same scene shown on a high-definition plasma screen, or a blank wall. The heart rate of people who looked at the scene through the window dropped more quickly than the others. In fact, the high-definition plasma screen had no more effect than the blank wall.

In addition, the research done through the Human Interaction with Nature and Technological Systems Lab at the University of Washington showed that when people spent more time looking at the natural scene their heart rates tended to decrease more. That was not the case with the plasma screen.

The study, funded by the National Science Foundation, is published in the current issue of the Journal of Environmental Psychology.

"Technology is good and it can help our lives, but let's not be fooled into thinking we can live without nature," said Peter Kahn, a UW associate professor of psychology who led the research team.

"We are losing direct experiences with nature. Instead, more and more we're experiencing nature represented technologically through television and other media. Children grow up watching Discovery Channel and Animal Planet. That's probably better than nothing. But as a species we need interaction with actual nature for our physical and psychological well-being."

Part of this loss comes from what the researchers call environmental generational amnesia. This is the idea that across generations the amount of environmental degradation increases, but each generation views conditions it grew up with as largely non-degraded and normal. Children growing up today in the cities with the worst air pollution often, for example, don't believe that their communities are particularly polluted.

"This problem of environmental generational amnesia is particularly important for children coming of age with current technologies," said Rachel Severson, a co-author of the study and a UW psychology doctoral student. "Children may not realize they are not getting the benefits of actual nature when interacting with what we're calling technological nature."

To see how people reacted to nature and a technological representation of it, the researchers recruited 90 college students to participate in an experiment that had them work on four mental tasks while sitting at a desk in an office. With 30 of the students, the desk faced a window overlooking a campus scene that included a large fountain and trees. For a second group of 30 students, the window was replaced with the plasma screen that showed the same nature scene in real time. For the remaining 30 students, curtains covered the plasma screen and the desk faced a blank wall.

Participants were tested individually. Each was welcomed by a researcher, hooked up to a heart rate monitor and told to wait for five minutes while the researcher stepped out of sight. A camera mounted on the wall near the window or plasma screen was synchronized with the heart monitor and tracked participants' eye movements. At the end of the waiting period, the researcher returned, explained the first task and stepped out of sight. This was repeated for the remaining three tasks and then the subject was told to wait again for five minutes.

Heart recovery rate was based on how quickly each participant's heart rate dropped in the 60 seconds after being told to wait or to have one of the tasks explained. Each person's performance was tallied on the basis of six measurements, once after every task and the two waiting periods. Low-level stress was created by having to deal with another person in a social situation and the anticipation or performance anxiety each might have experienced to do well on the four tasks.

The researchers found that participants with the plasma screen actually looked at it just as often as did those who had the window. However, the window held the students' attention significantly longer than the plasma screen did. When participants spent more time looking at the window, their heart rates decreased faster than on tasks when they spent less time looking at the window. This was not true with the plasma screen.

"I was surprised by this," said Kahn. "I thought the plasma screen would come somewhere between the glass window and the blank wall. This study is important because it shows the importance of nature in human lives and at least one limitation of technological nature.

"In the years ahead, technological nature will get more sophisticated and compelling. But if it continues to replace our interaction with actual nature, it will come at a cost. To thrive as a species, we still need to interact with nature by encountering an animal in the wild, walking along the ocean's edge or sleeping under the enormity of the night sky."