Development across the Life Span 333surroundings of home, even though Ainsworth’s experimental observers also observed the
infants and mothers in the home prior to the Strange Situation setting (Ainsworth, 1985).
Other research has found results supporting Ainsworth’s findings in home-based assess-
ments of attachment (Blanchard & Main, 1979). Other studies have also found support for
the concept of attachment styles and stability of attachment over the first 6 years of life
(Lutkenhaus et al., 1985; Main & Cassidy, 1988; Owen et al., 1984; Wartner et al., 1994). Even
adult relationships can be seen as influenced by the attachment style of the adult—those
who are avoidant tend to have numerous shallow and brief relationships with different
partners, whereas those who are ambivalent tend to have repeated breakups and makeups
with the same person (Bartholomew, 1990; Hazan & Shaver, 1987; Schroeder, 2014).
INFLUENCES ON ATTACHMENT As day care has become more widely acceptable and
common, many parents have been concerned about the effect of day care on attachment.
Psychologist Jay Belsky and colleagues (Belsky, 2005; Belsky & Johnson, 2005; Belsky et al.,
2007) have studied the attachment of infants in day care and concluded that although
higher quality of day care (small child-to-caregiver ratio, low turnover in caregivers, and
caregivers educated in child-care techniques and theory) is important, especially for cog-
nitive development, positive development including attachment was more clearly related
to the quality of parenting that the infants and toddlers received at home.
Although there are some cultural differences in attachment—such as the finding
that mothers in the United States tend to wait for a child to express a need before try-
ing to fulfill that need, while Japanese mothers prefer to anticipate the child’s needs
( Rothbaum et al., 2000), attachment does not seem to suffer in spite of the differences in
sensitivity. Evidence that similar attachment styles are found in other cultures demon-
strates the need to consider attachment as an important first step in forming relationships
with others, one that may set the stage for all relationships that follow (Agerup et al.,
2015; Hu & Meng, 1996; Keromoian & Leiderman, 1986; Nievar et al., 2015; Posada et al.,
2013; Stefanovic-Stanojevic et al., 2015). Before leaving the topic of attachment, let’s take
a look at one of the first studies that examined the key factors necessary for attachment.
Classic Studies in Psychology
Harlow and Contact Comfort
As psychologists began to study the development of attachment, they at first assumed
that attachment to the mother occurred because the mother was associated with satisfac-
tion of primary drives such as hunger and thirst. The mother is always present when the
food (a primary reinforcer) is presented, so the mother becomes a secondary reinforcer
capable of producing pleasurable feelings. to Learning Objective 5.5.
Psychologist Harry Harlow felt that attachment had to be influenced by more than just the
provision of food. He conducted a number of studies of attachment using infant rhesus mon-
keys (Harlow, 1958). Noticing that the monkeys in his lab liked to cling to the soft cloth pad used
to line their cages, Harlow designed a study to examine the importance of what he termed con-
tact comfort, the seeming attachment of the monkeys to something soft to the touch.
He isolated eight baby rhesus monkeys shortly after their birth, placing each in a cage
with two surrogate (substitute) “mothers.” The surrogates were actually a block of wood
covered in soft padding and terry cloth and a wire form, both heated from within. For half
of the monkeys, the wire “mother” held the bottle from which they fed, while for the other
half the soft “mother” held the bottle. Harlow then recorded the time each monkey spent
with each “mother.” If time spent with the surrogate is taken as an indicator of attachment,
then learning theory would predict that the monkeys would spend more time with whichever
surrogate was being used to feed them.