the ability to generalize study findings to the real world, is a subcategory of external validity. Another example highlighting the differences between these terms is from an experiment that studied pointing—a trait originally attributed uniquely to humans—in captive chimpanzees. This study certainly had external validity because when testing if captive chimps will gesture towards food by pointing, the results were reproduced in different trials and under different conditions. Nevertheless, The ecological validity and mundane realism of this study came into question because researchers were attempting to do cognitive research while disrupting these animals’ natural environment. Because the experimental conditions that are conducive to pointing (i.e. watching humans point) will never be experienced by chimpanzees outside the laboratory, this study is by definition lacking mundane realism. Furthermore, pointing doesn't emerge in wild chimpanzees; therefore, one could argue that because captive chimps were taken out of their natural environment, there is no point in studying a trait that wasn't adaptive through natural selection (holding no ecological validity). However, a counter-argument to this claim is that captive chimpanzees are under the ecological framework merely by existing. It is plausible that captivity is the context that leads to the development of this trait. Furthermore, if this trait can be taught to captive chimpanzees, it is certainly possible that if faced with particular circumstances, wild chimpanzees would also learn to point. Thus, ecological validity is a sliding scale. Humans have dramatically changed the natural world to the extent that behavior traits that animals adapt in response to human intervention (such as pointing) could technically hold ecological validity. With this in mind, perhaps instead of attempting to broaden the definition of this term, a new term should be identified to define traits that have only immerged due to direct human interference. See also Construct validity Content validity External validity Statistical conclusion validity References Validity (statistics)