
Diagram of two strong ties and a weak tie based on the principle of triadic closure. [3]

Diagram of two strong ties and a weak tie based on the principle of triadic closure. [3]

In human chemistry, a strong tie, as contrasted with a weak tie, is a strong connection that exists between two people. The principle of triadic closure argues that if two unacquainted people have a ‘strong’ relationship to a third person, who is common to them both, then by virtue of that indirect connection, a weak association or ‘tie’ will then begin to exist between the two previously unacquainted people. [1] Strong ties are depicted by straight lines (

) whereas weak ties are depicted by dashed lines ( – – – – – – ). The weak tie / strong tie theory was conceived by American sociologist Mark Granovetter in 1969 based on hydrogen bonding models. [2]

References
1. (a) Thims, Libb. (2007). Human Chemistry (Volume One) (weak ties, strong ties, pg. 184) . Morrisville, NC: LuLu.
(b) Thims, Libb. (2007). Human Chemistry (Volume Two) (weak ties, strong ties, pgs. xiv, 543, 548, 560, 574-78). Morrisville, NC: LuLu.
2. Granovetter, Mark. (1973). "The Strength of Weak Ties" (cited by 15367), American Journal of Sociology, Vol. 78, Issue 6, May 1973, pp. 1360-1380.
3. Easley, David and Kleinberg, Jon. (2010). Networks, Crowds, and Markets: Reasoning About a Highly Connected World (ch. 3: Strong and Weak Ties, pgs. 47-84). Cambridge University Press.