James Kennedy said this quote

More importantly, it is difficult to study minds because we are mental beings. We have our own minds to maintain and protect, and may not wish to discover facts that force us to change, or make us question our own being in the world, or conflict with our sense of right and wrong. We have not discussed belief systems known as religions to any extent in this book. However, particularly threatening are facts that run counter to ourreligious beliefs, especially if those beliefs are strongly held. Further, scientists have hopes, standards, and ethical beliefs, and they—like anybody—are not eager to find that their beliefs are invalid.