A different part of you when you speak another language?
Someone that I highly respect, who has a masters degree in Spanish, told me that when you speak another language it's like a different part of you comes out and you have a slightly different personality. When you speak something else you're using another part of your brain because a different language is a different way of thinking so you change a little bit.
What do you think of this? Do you agree or not? Why?
20 Answers
When I try to speak Spanish, I get this urge to dress like a lumberjack, but when I try to speak French, the urge is to dress in women's clothes and hang around in bars.
(apologies to Monty Python) 
Oh, come now! What a load of crock! I have never heard of anything so silly, unscientific and baseless as this! I speak English and Spanish constantly all day long, and I am the same sweet, loving, witty and humble guy no matter what I speak! Sheesh!!!
(Por favor no le hagan caso a mi colega angloparlante. Aquí entre nos, creo que está un poco mal de la cabeza, aunque en realidad no es mal chico. Discúlpenlo. Estoy seguro de que la teoría tiene un sólido fundamento en la praxis científica, y seguramente es tal como se dice allí.)
There could definitely be something to this. For one thing, the symbol sets you use (words) affect how you think (ideas). If you don't have a symbol for an idea you can't think about it. Second, most people who become fluent in a language also absorb part of the culture that language is associated with. It makes sense, though I think in most cases it's pretty subtle.
I read a true story that a English girl was brought up among the Masai tribe (the very tall, thin handsome race) in Africa and learned their language as a very young child.
She then returned to England among a very formal, serious society. When she was grown she took a trip back to the land of the Masai and when she encountered someone from its tribe, the language came back to her, she became intensely animated in speaking, and her emotions blossomed once more!
That story was very enlightening about how language affects us.
I completely agree with this. I speak several languages and each time I switch to another one I seem different to myself, each language makes me feel and think differently. But I find Spanish the most passionate! 
At about age 12, puberty, there is a coating on the brain cells, myelin, that finishes growing. This coating makes it harder to learn a second language. But it can be done. After brain damage to the parts of the brain where language is processed, other parts of the brain can take over the lost functions. Similarly, while someone is becoming fluent in a second language, the new brain cells being developed are not yet fully integrated with the older ones. When that full integration occurs and the parts of the brain responsible for personality have equal connections to both languages, you will see the phenomenon that Dogwood describes.
Someone at the clinic noticed that one of our practioners "took on a different persona" when she switched from English to Spanish. For those of us who are not fluent in both languages, I believe we do act and respond differently. But, from what I have noticed, people who are fluent and experienced in both languages rarely appear "different". They appear to flow between languages with a fluid ease.
That's a good observation.
This is a real question.
The answer is 'yes'. Every language is in some way different. When one word exists in one language, it may not exist in others. In one language you can describe your feelings, and in other you just can't name it, so it makes you, that you don't really have such feeling. My native language is polish, but many times I speak to myself in french, german, spanish or english. Every time I change the language, I think in a different way. Think of japanese - many homophones, so they can't describe everything very clearly, and this makes a barrier. The pronunciation is important too. For example - in french you say something slightly and in polish you say it a little bit more hardly.
A possible corrolary to what everyone is saying about symbol-sets and absorbing different cultures, words for different concepts existing in different languages might be that as we learn more languages we actually become richer, fuller people, with more ways of seeing the world, and a larger variety of ways to interpret our experiences.
Nuboso has hit upon a very profound truth about learning language and personality.
..to weigh in or not to weigh in...
hmmm...I do speak two other languages somewhat fluently ... I speak publically and even hold seminars and/or training sessions in other than my native English. I also hope to speak Spanish fluently someday, too, (although my first goal it to understand it completely, being much more interested in what people will have to say or in books I want to read than talking myself),
But think about it as hard as I might, I don't think I have a different personality at all ...no, not at all.
That does not mean that I do not think that this cannot be true for others. As I pointed out in a comment: as a small child, my daughter would begin using her hands "wildly" - gesticulating, really employing many gestures I know and love from watching Italians talk, -- whenever she switched from either German or English (both of which she also spoke without accent) to Italian. My daughter also speaks fluent unaccented Spanish (Colombian), and I watch her speaking with her husband sometimes --, but I do not sense otherwise a personality change. No, not at all.
I totally agree. I think Spanish is a much more emotional and passionate language and I feel like I can express things better in Spanish than in English. On the other hand, It seems like in English we try hard to dumb things down as much as possible and we try to take a lot of emotion out of our everyday speech. Also, I can relate to Ian-Hill. I used to dread public speaking until I started making speeches in Spanish. I think part of it is being so focused on correct pronunciation and sounding good that you don't have time to think about your audience. Also, it is easier to make mistakes in your non-native tongue because you are not expected to be perfect.
I think I'm much more considerate and friendly when I'm in a Spanish environment and speaking Spanish. My wife has noticed this and says she prefers the Spanish guy socially!
When I speak spanish I get the babes. When I speak English I
get slapped. 
This is very, very interesting and I am on the side that it does (somehow) draw out a different part of us. Learning a different language (along with an instrument) is after all one of the methods suggested for older people to keep the brain nice and fresh! My son has observed that when I am speaking Spanish with my friends I have a tendancy to wave my arms around a lot. (He thinks it's weird!) 
