  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.
