Does willingness to aid "others" change when in their physical presence? We argue that studies cueing non-coethnics through names and photos may underestimate discrimination resulting from actual interethnic interaction. In an experiment in Kabul, Afghanistan, Dari-speaking day-laborers contribute their earnings to a hospital under one of three randomly-assigned experimental conditions. In In-group, the hospital is in a Dari-speaking province; in Out-group-Abstract and Out-group-Real, it is in a Pashto-speaking (Pashtun) province. While subjects in In-group and Outgroup- Abstract wait for the experiment with only Dari-speakers present, subjects in Out-group-Real wait among both Dari-speakers and Pashto-speakers. When Pashtuns are absent, the findings accord with other experiments that find little to no out-group discrimination. However, the physical presence of Pashtuns (Out-group-Real) decreases contributions by 25%. Consistent with the threat hypothesis, contributions decrease the longer Dari-speakers wait with Pashtuns, though subjects' youth and ability to speak Pashto mediate this effect.