In a global study on atheism, sociologist Phil Zuckerman noted that countries with higher levels of atheism also had the highest suicide rates compared to countries with lower levels of atheism. He concludes that correlations does not necessarily indicate causation in either case.  A study on depression and suicide suggested that those without a religious affiliation have a higher suicide attempt rates than those with a religious affiliation.  A study into mental well-being in religious and non-religious people found that mental well-being for both religious people and non-religious people hinged on the certainty of their belief, and that previous studies had not controlled for the effect of belonging to a group when studying churchgoers.  Benjamin Beit-Hallahmi regarded atheists in Western society to be "much more likely to be a man, married, with higher education", and regarded the personality of atheists to be "less authoritarian and suggestible, less dogmatic, less prejudiced, more tolerant of others, law-abiding, compassionate, conscientious, and well educated. They are of high intelligence, and many are committed to the intellectual and scholarly life".  A review of the literature found that being non-religious did not necessarily entail poorer mental health.