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The available versions of the Vandenberg and Kuse (1978) Mental Rotations Test (MRT) have physically deteriorated because only copies of copies are available. We report results from a redrawn version of the MRT and for alternate versions of the test. Males perform better than females, and students drawn from the physical sciences perform better than(More)
The strongest sex differences on any cognitive task, favoring men, are found for tasks that require the mental rotation of three-dimensional objects. A number of studies have explored functional brain activation during mental rotation tasks, and sex differences have been noted in some. However, in these studies there was a substantial confounding factor(More)
Hemodynamic responses were measured applying functional magnetic resonance imaging in two professional piano players and two carefully matched non-musician control subjects during the performance of self-paced bimanual and unimanual tapping tasks. The bimanual tasks were chosen because they resemble typical movements pianists have to generate during piano(More)
We used self-reported direct finger measurements from 255,116 participants in a BBC Internet survey to investigate the measurement of 2D:4D ratios and their association with sex, ethnicity, and sexual orientation. We found significant sex differences such that males had lower 2D:4D than females and the effect size of the sex differences was greatest for(More)
Functional magnetic resonance tomography (fMRI) analysis of unimanual and bimanual sequential movements in righthanders showed the following effects. First, a rate-dependent activation of the somato-motor cortex was confirmed, with faster movement rates producing higher activation both in terms of signal intensity and number of activated voxels. Second, the(More)
In the common agency problem multiple mechanism designers simultaneously attempt to control the behavior of a single privately informed agent. The paper shows that the allocations associated with equilibria relative to any ad hoc set of feasible mechanisms can be reproduced as equilibria relative to (some subset of) the set of menus. Furthermore, equilibria(More)
In an Internet study unrelated to handedness, 134,317 female and 120,783 male participants answered a graded question as to which hand they preferred for writing. This allowed determination of hand preference patterns across 7 ethnic groups. Sex differences in left-handedness were found in 4 ethnic groups, favoring males, while no significant sex(More)
We introduce a game of complete information with multiple principals and multiple agents. Each agent makes a decision that can affect the payoffs of all principals. Each principal offers monetary transfers to each agent conditional on the action taken by the agent. We characterize pure-strategy equilibria and we provide conditions — in terms of game(More)
Purdue Pegboard performance of 16 male and 25 female right-handed college students were compared, and results were replicated with 25 male and 28 female subjects. In agreement with the literature, women performed significantly better than men. When measures of index finger and thumb thickness were used as covariate, all significant sex differences in(More)