Studies have pointed out that there are interesting correlations between the geographic extremes of Forest and Desert on the one hand, and a whole range of cultural predispositions on the other.

The basic claimed comparison is the table below, and the highlight is that Forests = polytheism, and Deserts = monotheism

This is simplistic. For example, we now equate the Sahara-Asian deserts with Islam, but historically the Arabian peninsula was overwhelmingly polytheistic, right up until Muhammad began trying to change it in 610 AD. (For an extensive critique of these ideas, and of the groups that disseminate them, see Steven Dutch’s page at the University of Wisconsin – Green Bay.)

However there are two lines of thought that can support the ideas of polytheism seeming more natural in a Forest environment, and of monotheism finding an easier reception in a Desert.

1. A Forest has abundant resources; a resource dispute can be solved by one party moving away. But the limited resources of a Desert will favor the party that uses violence to control the resources, and the need for violence will favor male power and stratified decision-making. A society dominated by a single powerful male will be more receptive to the idea of the Universe being under the control of a single powerful God.
2. In a Forest, nature has many aspects: trees, rivers, delicious fruits, poisonous fruits, animals you can eat, animals that will eat you, patches of sun, frequent rain, and so on. Nature is diverse, and its gods are diverse. In a Desert, nature is dominated by the sun – omnipresent, all-seeing, harsh, unforgiving, and an easy symbol for the domination of life by a single God.
   

   The sun - the inspiration for monotheism?

So a more complete comparison might be:

Does this mean that the Celts and Anglo-Saxons and Vikings coming out of the northern forests were non-violent? Hardly! But they were definitely more egalitarian, sexually tolerant and polytheist than the Latin cultures which subsequently dominated them.

You are unlikely to see Scandinavians stoning anyone to death for sexual promiscuity, or for pregnancy outside marriage.