As you have already read, meditating can cause some negative emotions to develop - such as anxiety, for example – rather than dissipate. Some research conducted at University College London, for example, found that individuals who meditate can find their psychological experience of the practice to be almost entirely negative. Perhaps this is because those people were predisposed to not enjoy meditating or because they went about it in a way that would almost ensure its failure. Whatever the reason, for every twelve or so people who enjoy meditating and find it fulfilling, there will be at least one who doesn't. This research is backed up by similar studies in Germany and Slovenia but also in some – but not all – ancient Buddhist texts. At the moment, science has only noted that meditating is something that not everyone can enjoy in the same way, but it has few answers as to why this may be the case.