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Tuesday, November 10th, 2015

    Time Event
    12:00a
    What counts as fair?

    There are many ways to divvy up a pile of cookies. Among the possibilities: Everyone can get an equal number, or those who contributed more to the cookie baking can get a larger share.

    In studies, young children usually default to splitting up resources equally. However, as children get older, they shift toward a merit-based approach, in which people who work harder on a task are rewarded with a bigger portion.

    New research from neuroscientists at MIT and the University of Rochester suggests that this shift is heavily influenced by children’s ability to count. In a study of children from the Tsimane’ tribe in the Amazon, who learn to count at widely varying ages, they found that counting ability was the biggest predictor of how children would divide resources.

    “It’s a very strong effect,” says Julian Jara-Ettinger, an MIT graduate student and lead author of the study, which appears in Developmental Science.

    The paper’s senior author is Steve Piantadosi, a former MIT graduate student who is now an assistant professor at Rochester.

    Calculating merit

    Despite numerous studies on the transition to merit-based resource distribution, there has been little agreement on why or exactly when it occurs.

    While much evidence suggests that the transition occurs around the age of 5 or 6, some studies have suggested that children as young as 3 will also distribute resources based on merit, but only if the number of items to be shared cannot be divided evenly. In those cases, children usually give extra items to those who worked harder.

    “There is evidence that even very young kids, if you force them to choose, they’ll give more to the person with more merit,” says Edward Gibson, a professor of brain and cognitive sciences at MIT and an author of the study. “It’s not that they don’t understand the concept of more merit, it’s just that they probably don’t know how to do the distribution.”

    A few years ago, Jara-Ettinger hypothesized that the transition to merit-based allocation might depend on the ability to count. In previous studies, it has been difficult to measure the effects of counting ability because for children in most industrialized societies, that ability is very closely correlated with age. However, in a 2014 study, Gibson’s team found that Tsimane’ children learn to count over a range of ages — usually between 5 and 8.

    During the new study, conducted over two visits to the Tsimane’ in 2013 and 2014, the researchers tested 70 children between the ages of 3 and 12.

    Each child was first shown two drawings of identical children with different colored shirts. They were told that the villagers had sent the two children to pick some bananas, and one child had worked very hard and brought back 18 bananas, while the other picked only four. The researchers then gave the children some paper cookies (always an even number) and asked them to distribute them as a reward.

    The researchers also tested the children’s ability to count, measured by the same test used in their 2014 study. An analysis of the data revealed that counting ability strongly predicted whether the children would distribute more cookies to the child who worked harder. However, age and years of education did not. 

    “We have known that understanding numbers is very important for thinking about mathematical ideas, but what’s striking is the finding that it also shapes how we think about things like our judgment of what’s fair. It goes beyond math into the social domain,” says Susan Levine, a professor of psychology at the University of Chicago who was not involved in the research.

    Manipulating objects

    It appears that while children understand the concept of rewarding more effort before they learn to count, they can’t accurately translate that into a distribution that reflects each person’s contribution, the researchers say. In a related study, not yet published, they have found that as children learn to count, they also gain an understanding of how sets of objects change as you add items or remove them.

    “Once they understand how sets of objects change as you manipulate them, that helps them reason more fluently about how to transform the sense that someone deserves more into deciding exactly how much more,” Jara-Ettinger says.

    One of the paper authors, Celeste Kidd at Rochester, is now studying whether the correlation between counting ability and merit-based distribution also appears in American children, who usually learn to count around the age of 3 or 4.

    2:00p
    DOE’s Kenderdine outlines nation’s energy priorities

    Melanie Kenderdine, as the first executive director of the MIT Energy Initiative (MITEI), helped to launch an international program to increase women’s participation and leadership in the energy field called Clean Energy Education and Empowerment, or C3E, in 2012.

    Last Thursday, Kenderdine, now the director of the Office of Energy Policy and Systems Analysis at the U.S. Department of Energy, returned to MIT to give the keynote address at the fourth annual U.S. C3E Women in Clean Energy symposium and awards program. Creating this event to recognize women in a variety of energy disciplines at all stages of their careers, she said, “was one of the most rewarding experiences I’ve ever had.”

    In her talk at the two-day MITEI event, Kenderdine focused on the DOE’s recently released Quadrennial Energy Review, a project initiated by Secretary of Energy Ernest Moniz, MITEI’s former director, to outline priorities for the nation’s energy research and policies over the coming years. The report, she said, gives a sense of the “key drivers and challenges” in the field of energy.

    Kenderdine began by recapping the scientific understanding of the threat of climate change, using a depiction of the probabilities of various outcomes developed by Ronald Prinn, co-director of MIT’s Joint Program on the Science and Policy of Global Change.

    Prinn used a pair of roulette wheels to starkly communicate the dangers of inaction: The wheel reflecting the probabilities under a “business as usual” scenario shows a significant probability of an average temperature increase of 7 degrees Celsius by the century’s end — an outcome that Kenderdine deadpanned would be “shall we say, transformational for the planet.” (Most scientists agree that any increase of more than 2 C could produce catastrophic results.)

    But that outcome is far from predetermined, she emphasized. In the corresponding roulette wheel, assuming that the world’s nations agree to substantial curbs in greenhouse gas emissions, the probability of exceeding that limit drops substantially. And there are indeed many options available to make such reductions practical, Kenderdine said.

    Showing a chart of the sources and uses of the world’s various kinds of energy, Kenderdine pointed out that almost half of the world’s energy is wasted. Curbing even a fraction of that waste could make substantial dents in emissions.

    That’s only one piece of the puzzle, since with growing population and rising standards of living, the world will consume a projected four times as much energy by 2100 as is used today, Kenderdine said. But there are some encouraging signs already.

    Greenhouse gas emissions have actually been declining slightly, for example, even as world GDP has increased — providing a stark refutation of claims that the two measures change in lockstep. This is partly due to a dramatic shift from coal to natural gas, she said — a change largely enabled by DOE-funded innovations: “The DOE invested heavily in shale gas technology,” Kenderdine said.

    But because energy industries are capital-intensive, with expensive plants built to operate for many decades, it is essential to have clear priorities for future development, so as to avoid huge investments in plants whose energy may grow incompatible with future economic and regulatory conditions.

    One key need, Kenderdine said, to enable the new energy developments that are most needed, is a drastic modernization of the electric grid, which has grown up piecemeal over the last century. Another priority is to enhance the resiliency and reliability of the nation’s existing energy systems, she said.

    For example, Kenderdine pointed out, 10 percent of the nation’s oil supply — the Strategic Petroleum Reserve — is held in tanks at a single location in Cushing, Oklahoma — right in the middle of “Tornado Alley.” And over 50 percent of the nation’s refining capacity is along the Gulf Coast, an area susceptible to intense hurricanes.

    Some needed changes are in the regulatory domain, Kenderdine said. For example, current federal laws on replacing energy infrastructure after a natural disaster require replacing a facility as it was before the disaster, rather than allowing for modernization or improvement.

    Another area where modernization is desperately needed, she said, is in natural gas delivery: Many gas lines in cities are decades old. Recent explosions in major cities have shown the dangers of leaking gas pipes, and the need for replacing those old pipes: An explosion that leveled an apartment complex in New York last year, for example, involved a pipe system that was 104 years old. Boston, Kenderdine pointed out, has had thousands of gas leaks reported in the last few years, compared with just a handful in similarly sized Indianapolis, which modernized its pipes a few years ago.

    The DOE’s Quadrennial Energy Review, Kenderdine said, includes 63 specific recommendations, which would likely have a total cost of $10 billion to $12 billion over the next decade. But there are great opportunities for improvements, particularly in the developing world, she said, where in many cases it may be possible to move directly into more efficient, modern generating and distribution systems.

    Such developments, Kenderdine said, can “make a huge difference in people’s lives.”

    The C3E symposium and awards program is a partnership of DOE and MITEI, under the auspices of the multi-governmental Clean Energy Ministerial.

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