请英文很好的朋友帮我搜索关于phobia的一些材料！急！

需要的材料是19世纪以来人类对于phobia是先天的还是后天的研究的演进！只要把找到的内容复制过来就好了，多多益善！但不要走题，不方便的话说下页面网址也行。（我英文不差，只是这些专业性的东西不太了解，而且需要尽量多的材料）
急用，感谢！有理想的答案会再加分！
是要英文的~3Q~~

only found this. hope it works

It is generally accepted that phobias arise from a combination of external events and internal predispositions. In a famous experiment, Martin Seligman used classical conditioning to establish phobias of snakes and flowers. The results of the experiment showed that it took far fewer shocks to create an adverse response to a picture of a snake than to a picture of a flower, leading to the conclusion that certain objects may have a genetic predisposition to being associated with fear. Many specific phobias can be traced back to a specific triggering event, usually a traumatic experience at an early age. Social phobias and agoraphobia have more complex causes that are not entirely known at this time. It is believed that heredity, genetics, and brain chemistry combine with life-experiences to play a major role in the development of anxiety disorders and phobias.