A venturesome hypothesis has been put forth by Wilson (1984), Kellert
(1996), and others and has been receiving increasing support. The hypo
thesis asserts the existence of biophilia, a fundamental, genetically
based human need and propensity to affiliate with other living organis
ms. A review of the biophilia literature sets into motion three overar
ching concerns. One focuses on the genetic basis of biophilia. A secon
d focuses on how to understand seemingly negative affiliations with na
ture within the biophilic framework. A third focuses on the quality of
supporting evidence and whether the biophilia hypothesis can be disco
nfirmed. Through this critical examination, biophilia emerges as a val
uable interdisciplinary framework for investigating the human affiliat
ion with nature. Yet it is clearly a nascent framework, and some of it
s potential lies in charting a stronger ontogenetic course. Toward thi
s end, in the second half of this article a structural-developmental a
pproach is framed for investigating biophilia. Support for this approa
ch is provided by discussing the author's recent studies-conducted in
the United States and in the Brazilian Amazon-on children's environmen
tal reasoning and values. (C) 1997 Academic Press.