Founded by Wertheimer (remember your German pronunciation - "W" = "V"), Köhler (say, "Kurler") and Kofka, sometime in late 1800s or early 1900s. Gestalt Psychology had one overriding motto: "The whole is greater than the sum of the parts." They used the phi phenomenon as an example: If you have two lights a short distance apart and you turn one on and within a second or so, turn on the second one, the light will appear to move from the first light to the second. This is called the "Phi Phenomenon."
The phi phenomenon is what makes movies "move." If you just look at the frames separately there is no movement. If you analyse the situation into its component parts, you would never see the phenomenon.
Or, take a chocolate cake. You can put the separate ingredients on the counter and study them till the cows come home and still not know anything about a chocolate cake. To really understand a chocolate cake, you have to mix all the ingredients together and bake them. You have to the study the whole, not the individual ingredients. This is why the gestaltists said "The whole is greater than the sum of its parts." You can see why they objected to the structuralists who tried to study consciousness by analysing it into its separate parts.
The Gestalt School focused mainly on perception, but they also objected to the behaviorists' analysing behavior in the same way the structuralists analysed consciousness. In contrast to the behaviorists, gestaltists thought learning did not by gradually putting together little itty-bitty S-R connections, but occurred by insight — all at once in its complete form.
One of their star pupils was "Sultan", a chimpanzee who figured out how to get a bananna hanging just out of reach by putting two sticks together. The chimp "studied" the situation for a while and then a light bulb suddenly appeared over his head. He connected the two sticks, marched over to the hanging banana, and promptly knocked it down using his newly invented tool. The gestaltists pointed out that the chimp didn't have to make any little prior responses that had to be associated with little stimuli, he just seemed to understand the total situation and ambled over and took the banana.