a criticism of learning theory is that it is largely based on studies with non human animals, such as skinners research with pigeons. it may lack validity because they present an oversimplified version of human behaviour.
contradicted by harlow, who suggests that feeding has nothing to do with attachment. the monkeys were attached to mothers that provided comfort and contact not food. supported by Shaffer and emerson
one strength, infants do learn through association and reinforcement, but food may not be the main enforcer. or may be that attention and responsiveness from a caregiver are important rewards.
learning theory may not provide a complete explanation of attachment but it still has some value.