Neuroscience
The hungrier an animal becomes, the more risks it's prepared to take in the search for food. Now, for the first time, Mkael Symmonds and colleagues have shown that our animal instinct to maintain a balanced metabolic state influences our decision-making in other contexts, including finance.
Nineteen male participants performed the same gambling task on three occasions, a week apart: either after a fourteen hour fast; immediately after eating a standard two-thousand calorie meal; or one hour after eating a two-thousand calorie meal. The task simply required participants to choose repeatedly between pairs of gambles, one of which was always riskier but more lucrative than the other.
The immediate effect of the meal was to neutralise risk aversion. For the men with more adipose tissue and higher baseline levels of leptin (a hormone that suppresses appetite), who are generally more risk averse, this meant they became less risk averse when performing the task right after eating. By contrast, for men with less adipose tissue and lower leptin levels, who are generally low risk averse, their risk aversion was increased immediately after eating, just as you'd expect based on the behaviour of hungry animals.
An hour after eating gives time for hormonal effects to kick in. As expected, men who reported feeling less hungry an hour after eating, and whose levels of acyl-ghrelin (a hormone that increases appetite) in the blood stream had fallen, played the gambling game in more cautious fashion. 'This parallels findings in foraging animals,' Symmonds told the Digest, 'where changes in metabolic state promote changes in behaviour to maintain or reach a metabolic benchmark (to take more risk if intake rate is relatively low, and less risk if intake is relatively high), but here we see the effect in the economic domain.'
The researchers said their findings have implications for understanding the behaviour of dieters, the obese and people with eating disorders. 'Prandial ghrelin suppression is reduced in obesity,' Symmonds and his co-authors wrote. 'Thus we predict greater risk-seeking in obese individuals following feeding, augmented by larger immediate post-prandial effects on risk taking due to higher baseline adiposity. This mechanism may underpin a component of the aberrant decision-making seen in obese individuals, including impulsivity and reward-seeking behaviour. We also predict profound effects on decision-making for individuals operating at very low baseline energy reserves [i.e. dieters and people with eating disorders]'
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Symmonds, M., Emmanuel, J., Drew, M., Batterham, R., & Dolan, R. (2010). Metabolic State Alters Economic Decision Making under Risk in Humans. PLoS ONE, 5 (6) DOI: 10.1371/journal.pone.0011090
Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.
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Neuroscience
How hunger affects our financial risk taking
Nineteen male participants performed the same gambling task on three occasions, a week apart: either after a fourteen hour fast; immediately after eating a standard two-thousand calorie meal; or one hour after eating a two-thousand calorie meal. The task simply required participants to choose repeatedly between pairs of gambles, one of which was always riskier but more lucrative than the other.
The immediate effect of the meal was to neutralise risk aversion. For the men with more adipose tissue and higher baseline levels of leptin (a hormone that suppresses appetite), who are generally more risk averse, this meant they became less risk averse when performing the task right after eating. By contrast, for men with less adipose tissue and lower leptin levels, who are generally low risk averse, their risk aversion was increased immediately after eating, just as you'd expect based on the behaviour of hungry animals.
An hour after eating gives time for hormonal effects to kick in. As expected, men who reported feeling less hungry an hour after eating, and whose levels of acyl-ghrelin (a hormone that increases appetite) in the blood stream had fallen, played the gambling game in more cautious fashion. 'This parallels findings in foraging animals,' Symmonds told the Digest, 'where changes in metabolic state promote changes in behaviour to maintain or reach a metabolic benchmark (to take more risk if intake rate is relatively low, and less risk if intake is relatively high), but here we see the effect in the economic domain.'
The researchers said their findings have implications for understanding the behaviour of dieters, the obese and people with eating disorders. 'Prandial ghrelin suppression is reduced in obesity,' Symmonds and his co-authors wrote. 'Thus we predict greater risk-seeking in obese individuals following feeding, augmented by larger immediate post-prandial effects on risk taking due to higher baseline adiposity. This mechanism may underpin a component of the aberrant decision-making seen in obese individuals, including impulsivity and reward-seeking behaviour. We also predict profound effects on decision-making for individuals operating at very low baseline energy reserves [i.e. dieters and people with eating disorders]'
_________________________________
Symmonds, M., Emmanuel, J., Drew, M., Batterham, R., & Dolan, R. (2010). Metabolic State Alters Economic Decision Making under Risk in Humans. PLoS ONE, 5 (6) DOI: 10.1371/journal.pone.0011090Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.
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Loneliness is bad for you. Some experts have even likened it to a kind of disease. What's unclear is how being being lonely leads to these adverse effects on our health. A new study looks at one possibility – that loneliness makes people feel hungrier...
- The Special Issue Spotter
Emotion and disorders of emotion (Nature Neuroscience). Sociologies of problem gambling (American Behavioural Scientist). Personality and personal relationship processes (Journal of Social and Personal Relationships). Making instructional cartoons...
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Too much noise, such as the sound of passing traffic, can increase the risk of heart attack in men by 50 per cent and in women by up to threefold. That’s according to a team of German researchers who interviewed 4,115 hospital inpatients, about half...
- The Hunger:
The PYY and Dopamine Issue Brain 'hunger pathways' pinpointed 12:05 15 October 2007 Anna Gosline The brain circuitry that influences how much food a person will eat – whether they feel starving or full – has been revealed by a new imaging...
- Neuropsychology Abstract Of The Day
Tinetti ME, McAvay GJ, Fried TR, Allore HG, Salmon JC, Foody JM, Bianco L, Ginter S, & Fraenkel L. Health outcome priorities among competing cardiovascular, fall injury, and medication-related symptom outcomes. Journal of the American Geriatrics Society....