Recently cultural theories of language evolution have gained significant momentum in explaining natural language. This paper reviews agent-based modeling, one of the key methodologies which is in part responsible for these developments. We discuss the most important challenges for a theory of cultural language evolution and the resulting dominant experimental paradigm. The discussion is framed along examples of experiments conducted within the methodology. We focus, in particular, on spatial language as an example of a complex and cognitively central domain treated in a series of robotic experiments. 1. Cultural Theories of Language Evolution Cultural theories of language evolution trace, explain and model the cultural development of the languages of the world. Explaining both the past and present of language is a daunting goal. The languages of the world have developed into ingenious systems for communicating enormous subtleties about the inner and outer world. An example of a part of language in which this creativity is very tangible is spatial language (Levinson, 2003; Svorou, 1994; Levinson & Wilkins, 2006). We know now from different studies in spatial language that human languages vary tremendously in how people, for instance, talk about the spatial configuration of objects. The following phrase from Tzeltal which is a Mayan language shows an example of a geocentric spatial language strategy (Brown & Levinson, 1993). (1) ay