The link above is an article that describes a study that was done and suggests that psilocybin, the hallucinogenic found in "magic mushrooms", can lead to a change in personality. The main change being studied is the participants' increase in their willingness to be open. In this case open meaning, "traits such as having imagination, a strong sense of aesthetics, a tendency to have a lot of feelings, enjoying abstract ideas, being broad-minded and being interested in learning and doing new things."
However, viewing this claim with the scientific thinking principles in mind, one may not be so open to believing in the magic.
1. The article does not rule out other hypotheses.
2. The article seems to be in favor of correlation equals causation. One must remember that correlation does not equal causation. There could possibly be a third, outside cause, of the participants' personality change.
3. This claim does not allow for falsifiability. It would be difficult to show if the psilocybin was or was not the cause of the personality change unless besides being given the same hallucinogenic, the participants had something else in common which could have caused the change in personality.
4. The article discusses how describes how the study was done which will allow for the study to be replicated to see if the same results are found.
5. The claim itself isn't very extraordinary and therefore doesn't need extraordinary evidence.
6. The claim is a simple one, following Occam's Razor.
Perhaps the reason that the results appear as they do is because of the way the study may have been done. The article makes it sound as if the study was not double blind. Therefore those who were studying the participants knew what they were looking for, but the participants were not sure what their reaction was supposed to be. The participants did know that they were being given psilocybin. If the study was not done double blind then there can be many explanations as to how the findings turned out the way they did.
Since the participants were given personality tests every couple of months they may have picked up on the demand characteristics of those conducting the study. Demand characteristics are, "cues that participants pick up from a study that allow them to generate guesses regarding the researcher's hypothesis" (Lilienfeld, 65). Also the researchers involved may have been victims of the experimenter expectancy effect. Since the researchers knew what the hypothesis was and wanted it to be true, they may have put some of their own bias into the results unintentionally.
Furthermore, the study fails to mention whether or not a control group was involved.