Cognitive turn and social turn approaches in cognitive psychology What is cognitive and social turn in (cognitive) psychology? 
Googling has not returned anything on this. I came across this in my lecture slides listed under possible Cognitive Psychology approaches, along with Introspection and Behaviourism.
There isn't a single, simple answer to this question. Instead, I would expect as many answers as there are theoretical foundations/schools within psychology. From a point of view grounded in Theory of Action I maintain: 

Behaviorism posits that behavior is learned in response to both combinations of stimuli (Pavlov) and reinforcing stimuli (Skinner). The processes inside the individual are reduced to the concept of reaction. 

The cognitive turn opened the so-called "black box" of the subject, reasoning, feeling and so on. Scholars left the "reliable terrain" of directly observable attributes of behavior and gave birth to theories which aim to both describe and explain the invisible internal psychic processes. One subjectively important milestone is the work by Miller, Galanter and Pribram: The individual is an actor. As such he/she doesn't just behave in reaction to external stimuli. He/she tests (plans) various alternative ways to act in a given situation within a cognitive representation of the environment. 

One example for a social turn in psychology is Social Cognitive Theory by A. Bandura. The actor does not just rationally plan the best way to reach a goal – he/she also reproduces the ways of acting experienced in the social system. Rationality is bounded by the norms of the social system. In other words, an actor acts in a particular way, even if it is dysfunctional, because it mirrors what significant others have done before. 

References: Literature about the cited works is readily available in both university libraries and the Internet. (Also: One of the textbooks by P. 
G. Zimbardo et al.)