People tend to call me a rationalist, and that's not really something I have a problem with. I don't think philosophical ideas should be a matter of identity ('being' a rationalist, as opposed to merely espousing rationalism), so in that sense I object to the label. But aside from that, I do think it is good to be rational. It is better to think, and to attempt to come to terms with what is true, rather than merely to feel and accept whatever is intuitive or emotionally-appealling.
There is, of course, no reason not to be rational, and it is impossible to defend any idea or claim without making a stab at reason at some point. Reason is important, as is finding out what is actually the case in the world - that's self-evident, I hope. It's also vitally important to have a functioning bullshit-detector, and if you're susceptible to religious or nationalist claims on emotional grounds then I consider your bullshit-detector to be basically broken.
But that doesn't mean that I don't have emotions about things. It's probably quite apparent from my other posts that I feel strongly about a range of topics, from academic language and Indo-European linguistics to racism and the nature of the universe. I just think it's wise to invest emotion in things that can be supported rationally.
Nazism was doubtless a stirring and empowering vision for unemployed and disenfranchised German men in the 1920s and 30s, but even then a sober analysis of the world would have undone all of the fundamental claims of the Nazi movement. No matter how appealling something like that is, if you can't find a good reason in the evidence from the world for following it then you should tear yourself away from it. If you tell yourself that it's not worth it because it's not true, you can find something that is actually worthy of your appreciation - a band, a painting, a pub, a bed, a person. Invest your emotion elsewhere, and think before you emote when it comes to the fundamental orientation of your life.
When it comes to identity - ethnic, racial, national, gender - I don't think it makes sense to invest any emotion in it. In looking into human history and prehistory around the world, admittedly sometimes in a cursory way, I have found that most of the things that people invest their emotion in are transient and of such recent origin that arguing in favour of their primordial nature is an absurdity. Since nearly all ethnic and national claims are based on some kind of primordialism, this rather takes apart the whole idea.
Variation in human skin tone and aptitude at altitude don't have an especially long pedigree (considering that the universe is nearly fourteen billion years old); nations come and go (and are, while they exist, generally models of internal diversity); ethnic groups seem to be largely strategic responses to situations instead of primordial and long-lasting independent entities. Most of the things a person would have pledged to and died for in 3000 BCE no longer exist, and I don't think it makes a lot of sense to die for, or even to think about very much, those things like nations and ethnicities that have such transient existences and which in any case live only in human heads.
And even if such things were objective, rather than merely intersubjective, and even if they had genuine, demonstrable, homogeneous correlates far into the ancient past, I still don't think they'd be worth dying for or considering particularly important. It seems to be a true statement that I am a mammal, and moreover that mammals have been around for about 200,000,000 years, but it's not something I'm interested in thinking about much (at least in terms of my own identity, emotion, and character). I don't see any reason to see race or ethnicity differently.
I do find it amazing that some things have surprisingly ancient origins, but that seems to be true of nearly all things, and I don't see any more excitement and interest in a proto-Indo-European word than in a proto-Mixe-Zoquean word merely because I happen to speak an Indo-European language as my mother tongue.
The purpose of being alive, as far as I can divine it, is to explore the universe - to find out what is the case, what the world is like, how things are, what it's like to feel all the weird sensations of the world. Actually, this is just what I have chosen to do with my life - it's not some immutable imperative for all living beings - but I do think it's a superior purpose to expressing and living out traditions or embodying ethnic and national norms or defending an in-group to the death. I think we should ditch whatever doesn't contribute to the free and peaceful exploration of the universe, and the main emotion I feel for flag-wavers and racists is pity.
Humans should restrain their (probably innate) ethnocentrism and embrace the world, the only one there is.