In thermodynamics, volume is an extensive quantity whose conjugate tension is pressure. [1] The elementary work exchanged with the surroundings by pressure forces is given by:

$dW = - P dV \,$

hence, a change in volume, dV, at a given pressure, enables the calculation of the the work done by the body during that process.

Overview
In 1778, French chemist Antoine Lavoisier, in his Elements of Chemistry stated the following, aka Boerhaave’s law:

“That every body, whether solid or fluid, is augmented in all its dimensions by any increase of its sensible heat, was long ago fully established as a physical axiom, or universal proposition, by the celebrated Boerhaave.”

In other words, adding heat to a body or system (volume) causes expansion, and this fact is a physical axiom long ago established phenomenon of nature.

Social volumes
See main: Social volume
The translation of the understanding of thermodynamic volume in human reactions in systems, e.g. a country, town, or territory, etc., is extremely difficult and is at the core of human thermodynamics. When translated over into the human sphere, where people are considered as “human particles” or "human molecules", however, the understanding of this expansion boarders on the cutting edge of modern knowledge.

In 2005, Ingo Muller, in his Entropy and Energy: A Universal Competition, discussed socio-thermodynamics, wherein he correlates pressure-volume boundary work to "part of the habitat lost', whether the habitat is atoms, molecules, birds or men. [4]

Studies show, for instance, that alpha males and alpha females are given more individual or personal space. A supermodel, someone who, according to common opinion, is considered physically "hot", when walking alone through a crowd of people will be given more personal space than as compared to a more homely female. [2] Moreover, when people are asked to approach a stranger and stop when they no longer feel comfortable, they will stop about two feet away from a tall person (22.7 inches to be exact) but less than a foot (9.8 inches) from a short person. As height is correlative with physical attractiveness, e.g. shorter than average men and women are less attractive than taller men and women, it is found, according to attractiveness researcher Nancy Etcoff, that “very attractive people of any size are given bigger personal space and territory; which they carry around with them.” [2] In other words, physically ‘hot’ molecules, in a sense, trigger volume increase be it a gaseous molecule or a human molecule. [3]

References
1. Perrot, Pierre. (1998). A to Z of Thermodynamics, Oxford: Oxford University Press.
2. Etcoff, Nancy. (1999). Survival of the Prettiest – the Science of Beauty. New York: Anchor Books.
3. Thims, Libb. (2007). Human Chemistry (Volume One), (preview). (ch. 8: “Planck’s quantum, pgs. 213-245). Morrisville, NC: LuLu.
4. Muller, Ingo and Weiss, Wolf. (2005). Entropy and Energy - A Universal Competition, (ch. 20: "Socio-thermodynamics", pgs. 203-21). New York: Springer.