 26. Naturalizing the Self 563
a naturalist view of the self, spearheaded by 
neuroscientists such as Crick (1994), Gazzan -
iga (1998), Edelman (2005), Ramachandran 
(2007, 2011), Dehaene (2014), Koch (2017), 
Stevens and Woodruff (2018), and others 
who study the neural mechanisms underlying 
consciousness in an attempt to understand 
how a sense of self emerges from the activity 
of the brain. Memory researchers have linked 
various forms of memory to the conscious 
experience of self (e.g., Tulving, 2005; Row -
lands, 2016), and examined neural activation 
during processing of self-  relevant informa -
tion (Kelley et al., 2002; Magno & Allan, 
2007). Baron-Cohen (2008), Ramachandran 
(2011), Ananthaswamy (2015), and others 
provide vivid illustrations of how neurologi -
cal disorders such as autism can produce pro -
found deficits in self and identity. Finally, nu -
merous clinical disorders involve self-  related 
problems such as distorted self-  perceptions 
and low, fragile, and contingent self-  esteem.
Thus, researchers from a wide range 
of perspectives outside of the traditional 
boundaries of personality psychology are 
grappling with basic issues about the self. 
Moreover, within personality (and social) 
psychology, an explosion of recent research 
has linked brain mechanisms to self-  related 
processes, including research on the neu -
ral bases of self-  esteem (Izuma, Kennedy, 
Fitzjohn, Sedikides, & Shibata, 2018), self- 
control (Berkman, 2018), pride (Takahashi 
et al., 2008), autobiographical memory 
(Levine, 2004), and cultural influences on 
self processes (Han, 2017; Han & Ma, 
2015). Building on this emerging biological 
account, researchers have speculated about 
the evolutionary origins of the self (Se -
dikides & Skowronski, 2003) and explored 
the genetics of self-  esteem and other self 
processes (e.g., Cai & Luo, 2017; Jonassain, 
2010; Neiss et al., 2005).
What unites many of these perspectives 
is a naturalist view of the self—a belief that 
the human self can be studied like any other 
natural phenomenon. One goal of this chap -
ter is to help self research recover its roots 
by reconnecting it with broader scientific 
concerns. To accomplish this goal, I will 
return to a set of foundational issues—  the 
ontogeny, biological basis, and evolutionary 
function of the self—that preoccupied Wil -
liam James when he formulated his natural -
ist perspective of the mind.Overview of the Chapter
The literature on the self is enormous. A 
survey of personality psychologists indicat -
ed that 43% of respondents study the self- 
concept and 35% study self-  esteem (Robins, 
Tracy, & Sherman, 2007). A PsycINFO 
search for the subject “self” identified over 
225,000 articles published in the past 30 
years, with over 1,500 articles appearing 
just in the Journal of Personality and Social 
Psychology.2
It is difficult to write a chapter about a 
topic that is so vast, arguably as vast as the 
entire field of personality psychology. In -
stead, in this chapter, I have chosen to focus 
on a particular perspective on the self, the 
naturalist perspective. Why a naturalist per -
spective? Because this perspective highlights 
aspects of the self that best connect with the 
realist orientation adopted by many, if not 
most, personality psychologists. In contrast 
to social constructionist accounts of person -
ality, a realist view takes as a given that peo -
ple have an essential nature that forms the 
core of human personality. In the same way, 
a naturalist view of the self assumes that our 
self-views are not simply self-  presentations, 
sociocultural constructions, or stories we 
tell about ourselves. They are real, essential 
qualities substantiated in memory and exert -
ing causal force on our thoughts, feelings, 
and behaviors.
Thus, my goal in this chapter is not  to pro -
vide a comprehensive review of the volumi -
nous literature on the self, but rather to step 
back and reflect on some broader questions 
about the self: What is the self? When does 
the self first emerge, and how does it change 
over time? Is the self distinctive to humans? 
How does the brain build a sense of self? Is 
the self a product of evolution? What are the 
adaptive functions of the self? These ques -
tions return us to James’s (1890) initial set of 
concerns when he formulated his naturalist 
perspective on self and consciousness.
Basic Questions about the Self
What Is the Self?: 
Definitional  and Conceptual  Issues
The question—  what is the self?—has been 
an abiding concern of philosophers, writ -
ers, scientists, and laypeople. Although self 