Mary Ainsworth (1913-1999) was a Canadian developmental psychologist, who is known for her description of attachment styles among children (secure, anxious-resistant, anxious-avoidant and disorganized) and a method for observing these styles, named the “strange situation”. With her research, Ainsworth provided empirical support for the attachment theory approach first introduced by English psychiatrist John Bowlby, with whom she collaborated.

See related lecture on attachment: What We All Need to Know About Attachment, Jon G. Allen