why a wooden spoon?

[Shaheen]

I want to know the reason behind using a wooden spoon in mixing a cake batter

 

[Haggis]

The only reason I can think of to specifically use a wooden spoon while mixing a cake batter is that it will not react to any of the ingredients used as might some metal utensils (although most metal utensils are made out of, or coated with, a non-reactive metal so this is not really an issue).

I think it comes down to the fact that wooden spoons are present in any kitchen so by specifying the specific implement to use it saves any confusion (instead of just saying 'use a spoon', believe me some people just can't handle that kind of ambiguity).