Paul Zak
Claremont Graduate University, Center for Neuroeconomics Studies, Faculty Member
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Oxytocin is a neuropeptide recently associated with social behavior in animals and humans, but the study of its function in populations with social deficits such as autism, schizophrenia, and social anxiety disorder has only recently... more
Oxytocin is a neuropeptide recently associated with social behavior in animals and humans, but the study of its function in populations with social deficits such as autism, schizophrenia, and social anxiety disorder has only recently begun. We measured plasma oxytocin in 24 patients with Generalized Social Anxiety Disorder (GSAD) and 22 healthy controls using an enzyme-linked immunosorbent assay. There were no significant differences in oxytocin level (pg/mL) between patients (M = 163.0, SD = 109.4) and controls (M = 145.0, SD = 52.9, z = 0.21, P= 0.8). Within the GSAD sample, however, higher social anxiety symptom severity adjusted for age and gender was associated with higher oxytocin level (R2= 0.21, β= 0.014, SE = 0.006, t = 2.18, P= 0.04). In addition, dissatisfaction with social relationships was associated with higher oxytocin levels (R2= 0.18, β=–0.20, SE = 0.10, t =–2.01, P= 0.05). Our data provide preliminary support for a link between social anxiety severity and plasma oxytocin. These findings may suggest a possible role for oxytocin as a facilitator of social behavior, an effect which may not be fully utilized in individuals with severe social anxiety.
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Research Interests: Neuroeconomics, Trust, Economics and Human Biology, Global Health, Neuroendocrinology, and 16 moreBehavioral Economics, Social Identification, Applied Economics, Social behavior, Oxytocin, Humans, Scaling up, Human health, Survey data, Estrogens, Food habits, Environmental Conditions, Social Behavior, Environment, Phytoestrogens, and Socioeconomic Factors
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... affiliation corticolimbic-striatal networks; appetitive and consummatory reward; dopamine; oxytocin; personality; social ... The binding of context into an ensemble that rep-resents the context of ... Finally, the neurobehavioral... more
... affiliation corticolimbic-striatal networks; appetitive and consummatory reward; dopamine; oxytocin; personality; social ... The binding of context into an ensemble that rep-resents the context of ... Finally, the neurobehavioral treatment of affili-ation would be incomplete from a trait ...
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Research Interests: Pharmacology, Biochemistry, Bioinformatics, Evolutionary Biology, Genetics, and 55 moreMarine Biology, Neuroscience, Environmental Science, Geophysics, Physics, Materials Science, Quantum Physics, Developmental Biology, Immunology, Climate Change, Molecular Biology, Structural Biology, Experimental games, Trust, Genomics, RNA, Computational Biology, Transcriptomics, Social Interaction, Biotechnology, Systems Biology, Cancer, Biology, Metabolomics, Risk, Cell Cycle, Proteomics, Ecology, Drug Discovery, Evolution, Nanotechnology, Astrophysics, Neurobiology, Medicine, Multidisciplinary, Palaeobiology, Functional Genomics, Investments, Nature, Signal Transduction, Astronomy, Biological Sciences, DNA, Social behavior, Oxytocin, Humans, Male, Cell Signalling, Medical Research, Questionnaires, Adult, Interpersonal Interaction, Social Behavior, Intranasal Administration, and Earth Science
Using property-rights tools, this paper develops a theory of the transition from despotic to rule-of-law regimes, relying on the notion that rulers and subjects are interested in maximizing wealth. Keeping subjects in check enhances... more
Using property-rights tools, this paper develops a theory of the transition from despotic to rule-of-law regimes, relying on the notion that rulers and subjects are interested in maximizing wealth. Keeping subjects in check enhances despots' internal security, but at the cost of lower output, and of less wealth for the despots. Enhanced wealth is especially valuable for protection against outside threat. Subjects will increase output only if provided with rights to, for example, ownership, movement, and voting. Despots can guarantee them these rights by relinquishing some of their own power.
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This paper develops an open economy theory of endogenous growth in which agents make fertility and migration choices that affect the rate of transmission of human capital from parents to children. The model produces both a poverty trap as... more
This paper develops an open economy theory of endogenous growth in which agents make fertility and migration choices that affect the rate of transmission of human capital from parents to children. The model produces both a poverty trap as well as a common balanced growth path, and shows that immigration has quite different implications for developing and developed countries. Developing
Research Interests: Demography, Research Methodology, Immigration, Migration, Economic Theory, and 13 moreFertility, Population Dynamics, Human Capital, Human Resources, Income Distribution, Applied Economics, Growth, Population, Developing Country, Open Economy, Endogenous Growth, Developed Countries, and Poverty Trap
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... Cross-Country Investiga-tion, 112(4) Quart. J of Econ 1252 (1997). 6 Robert D. Putnam,Bowling Alone : The Collapse and Revival of American Com-munity, (Simon & Schuster, 2001). 7 Our choice of policies was strongly... more
... Cross-Country Investiga-tion, 112(4) Quart. J of Econ 1252 (1997). 6 Robert D. Putnam,Bowling Alone : The Collapse and Revival of American Com-munity, (Simon & Schuster, 2001). 7 Our choice of policies was strongly influenced ...
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Empathy is related to a variety of prosocial behaviors, but the brain mechanisms producing the experience of empathy have not been fully characterized. This study investigated whether the experience of empathy raises oxytocin levels and... more
Empathy is related to a variety of prosocial behaviors, but the brain mechanisms producing the experience of empathy have not been fully characterized. This study investigated whether the experience of empathy raises oxytocin levels and affects subsequent generosity toward strangers. Short video clips of an emotional scene and an unemotional scene were used as stimuli. Participants rated the emotions they experienced and then played a $40 ultimatum game to gauge their generosity. We found that empathy was associated with a 47% increase in oxytocin from baseline. We also found the empathy–oxytocin response was stronger in women than in men. Higher levels of empathy were also associated with more generous monetary offers toward strangers in the ultimatum game. Our findings provide the first evidence that oxytocin is a physiologic signature for empathy and that empathy mediates generosity.
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Abstract A formal dynamic theory of the transition from a developing autocracy to democracy is presented in the context of a heterogeneous agent general equilibrium growth model. The theory shows that the primary determinants affecting... more
Abstract A formal dynamic theory of the transition from a developing autocracy to democracy is presented in the context of a heterogeneous agent general equilibrium growth model. The theory shows that the primary determinants affecting the timing of democratic transitions ...
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Recent biomedical research shows that roughly three-quarters of cognitive abilities are attributable to genetics and family environment. This paper presents a growth model that characterizes the role of the intergenerational transmission... more
Recent biomedical research shows that roughly three-quarters of cognitive abilities are attributable to genetics and family environment. This paper presents a growth model that characterizes the role of the intergenerational transmission of genes and the effect of family environment on growth trajectories. If the average human or physical capital stocks are sufficiently low, the model shows that the economy will be caught in a poverty trap. Conversely, countries with more resources will converge to a bala nced growth path where the average rate of genetic transmission of skills from parents to children determines the long-run rate of output growth. Increased genetic diversity (or income inequality) is shown to raise the fertility rate and reduce output growth in the transitional dynamics. Thus, nature and nurture are able to explain a variety of countries' growth experiences.
Research Interests: Genetics, Evolutionary Economics, Economic Growth, Economic Theory, Human Capital, and 11 moreGenetic Diversity, Income inequality, Family Environment, Fertility Rate, Cognitive Ability, Family Structure, Physical Capital, Intergenerational Transmission, Transition Dynamics, Poverty Trap, and Growth Model
Research Interests: Genetics, Psychology, Bioeconomics, Population Genetics, Economic Growth, and 17 moreSexual Selection, Population Biology, Fertility, Evolution, Human Capital, Informal Economy, Genetic Diversity, Growth, Old Age, Young Adult, Population Size, Population Growth, Economic performance, High Dimensionality, Intergenerational Transmission, Age Structure, and Family Size
The relationship between production lags and business cycles has a long history in economics, but was first analyzed rigorously by Michal Kalecki in 1935. In a linear delay differential equation model, Kalecki showed that production... more
The relationship between production lags and business cycles has a long history in economics, but was first analyzed rigorously by Michal Kalecki in 1935. In a linear delay differential equation model, Kalecki showed that production delays can endogenously generate cycles. Whether this result holds in general equilibrium has been an open question. An answer is provided by examining the effect of Kaleckian lags in the Solow and Cass-Koopmans growth models. It is shown that such models do produce endogenous cycles, confirming that Kalecki's model relating lags to cycles holds in general equilibrium settings.