https://blog.hubspot.com/marketing/intrinsic-and-extrinsic-motivation
https://www.verywellmind.com/what-is-intrinsic-motivation-2795385
https://www.verywellmind.com/what-is-extrinsic-motivation-2795164
https://www.psychologytoday.com/us/blog/insight-is-2020/201304/understanding-the-sociopath-cause-motivation-relationship
http://www.personalityresearch.org/papers/rabideau.html
