Terrestrial gamma-ray flashes (TGFs) from Earth's upper atmosphere have been detected with the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) satellite. The gamma-ray spectra typically extend up to 10 to 20 megaelectron volts (MeV); a simple bremsstrahlung model suggests that most of the electrons that produce the gamma rays have energies on the order of 20 to 40 MeV. RHESSI detects 10 to 20 TGFs per month, corresponding to approximately 50 per day globally, perhaps many more if they are beamed. Both the frequency of occurrence and maximum photon energy are more than an order of magnitude higher than previously known for these events.

This research provides the first support for a possible psychological universal: Human beings around the world derive emotional benefits from using their financial resources to help others (prosocial spending). In Study 1, survey data from 136 countries were examined and showed that prosocial spending is associated with greater happiness around the world, in poor and rich countries alike. To test for causality, in Studies 2a and 2b, we used experimental methodology, demonstrating that recalling a past instance of prosocial spending has a causal impact on happiness across countries that differ greatly in terms of wealth (Canada, Uganda, and India). Finally, in Study 3, participants in Canada and South Africa randomly assigned to buy items for charity reported higher levels of positive affect than participants assigned to buy the same items for themselves, even when this prosocial spending did not provide an opportunity to build or strengthen social ties. Our findings suggest that the reward experienced from helping others may be deeply ingrained in human nature, emerging in diverse cultural and economic contexts.

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