|Marilyn Monroe on attractiveness, nature, and spontaneity in respect to humans and sexuality.|
The work of Jacob Moreno and his theory of the social atom is largely based on his studies of the spontaneity level of children as compared to adults.
In 1995, American electrochemical engineer Libb Thims has been working to understand how the famous spontaneity criterion, i.e. ΔG < 0, of chemical thermodynamics applies to human spontaneity, particularly in the context of mate selection and marriage. This single thought experiment is what largely resulted in the world's first textbook on human chemistry. 
1. (a) Thims, Libb. (2007). Human Chemistry (Volume One). Morrisville, NC: LuLu.
(b) Thims, Libb. (2007). Human Chemistry (Volume Two). Morrisville, NC: LuLu.
● Barker, Wayne. (1968). Brain Storms: a Study of Human Spontaneity. Grove Press.
● Natekar, Chandrakanth. (2010). “Eternal Beauty of Human Spontaneity”, AuthorsDen.com, Apr 15.