the mind of another. Social scientists take two major approaches to understanding
human experience: through objective assessment using observation and through
subjective means by attempting to see the world through the eyes of another.
Anthropologists have termed these approaches“etic”and“emic,”respectively. An
extreme case of an etic approach to humans would involve using human ethology,
employing techniques used in studies of animal behavior to observe people without
actually conversing with the individuals under study. A more common etic
approach is the administration of structured questionnaires. Emic studies are
accomplished through open-ended communication with the other person, primarily
through language, but also through nonverbal communication. In simple terms, the
main method for learning about the experience of another person is to ask that
person to describe his/her experience, thus eliciting self-reports. Self-reports have
limitations, however, due to variability in self-awareness, difficulty in articulating
feelings, and diverse concepts of what is appropriate to report.
The“invisible”in the book’s title refers both to the hidden nature of some of
one’s own experiences, as well as to those experiences concealed within the head
and body of another person. The attempt by social scientists to understand and/or
reveal these hidden experiences is an attempt to make visible the invisible. This
book looks at the methods used to make individuals more aware of some of their
own experiences that are often unconscious or even misconstrued. The volume also
addresses methods that enhance self-reports with other means—particularly the use
of biological markers. This follows, for example, attempts to understand the“mind”
through clinical, subjective means in contrast to explorations of the“brain”by
neurobiologists. Different methodologies provide different insights into our com-
plex cognitive states.
This book also examines humans throughout the life span, since life experiences,
and awareness, change with age. Generally hidden from self-awareness are the
trade-offs that individuals must make between energetically expensive physiolog-
ical demands, such as somatic maintenance, immune function, physical activity,
growth, reproduction, and energy stores. Study of these trade-offs forms the
foundation of life history theory (Hill 1993 ). The basis of this theory is that
resources—e.g., energy and nutrients—are limited, and limited resources are bal-
anced across competing physiological demands (Stearns 1992 ). Evolution, based
upon reproductive success, will favor individuals who behave in such a way as to
maximize their long-termfitness by balancing reproductive effort with the expen-
diture of resources needed for growth, development, and the maintenance of their
own bodies. For instance, mothers are faced with a decision of when to wean their
infants, because high maternal investment in breastfeeding constrains the energy
available to support a new pregnancy (Ellison 2003 ). Early weaning shortens the
birth interval, enhancing reproductive success, but success may not be enhanced if
early weaning reduces thefitness of the current child.
2 D.E. Brown and L.L. Sievert