Social Spiral Pattern in Experimental 2x2 Games

With evolutionary game theory, mathematicians, physicists and theoretical biologists usually show us beautiful figures of population dynamic patterns. 2x2 game (matching pennies game) is one of the classical cases. In this letter, we report our finding that, there exists a dynamical pattern, called as social spiral, in human subjects 2x2 experiment data. In a flow/velocity vector field method, we explore the data in the discrete lattices of the macro-level social strategy space in the games, and then above spiral pattern emergent. This finding hints that, there exists a macro-level order beyond the stochastic process in micro-level. We notice that, the vector pattern provides an interesting way to conceal evolutionary game theory models and experimental economics data. This lattice vector field method provides a novel way for models evaluating and experiment designing.