According to Freud, the mind was made up of three parts: the id (biological instincts), the ego (the instinct's connection to external reality), and the superego (our inner policeman—he makes us feel guilty when we're naughty, helps us control our bad behavior).
When babies look at themselves in the mirror and think, "hey there's my body!", that "whole self" they see is called an imago (or Ideal-I). The Ideal-I is a stable organized self, which quickly becomes an ideal that pretty much has zero to do with the infant's actual experience. Though the baby recognizes himself as that image, he will undertake a lifelong quest to actually be that whole self—that Ideal-I. Spoiler alert: ain't gonna happen. That quest will never end, and that's why so many people are hot messes—anxious, neurotic, or even psychotic. The more you know...
No, we're not talking about your driver's license or passport. I like to take little common words and transform them into complicated terms of psychoanalytic theory. So when I say "identification," I'm actually referring to an intricate psychological response over which the subject can gain full control. Yikes—that's a mouthful. Bear with me here, people.
Identification takes place when an object (usually a person) in the big wide world fascinates the subject (also a person). That subject then turns that object/person into part of his self-image (as in, by getting a Justin Bieber haircut, you are identifying with—you guessed it—the Biebs). The initial stage of identification is the mirror stage, where the baby gets all wrapped up in his own image. He quickly moves on to other images, because you can only stare yourself in the face for so long before you're totally creeped out.
This here's my critical revision of Freud and my biggest contribution to psychoanalytic theory. It's super complicated, and even I have trouble explaining it, but here goes: When a child is born, he must develop an ego (which means a sense of self—an "I"—not a big head). By the time that child is six months old, he develops his own little ego through identification. Identification comes about when the baby sees himself in a mirror and sees that he has a whole body (and isn't just separate hands, a mouth, eyes, etc.).
Once that recognition happens, and the baby realizes, "Wow! I'm an object, something that other people look at," things get strange. The baby experiences that feeling as really weird: "How can I be me and that be me at the same time? That's funny; I don't feel as complete as I look in that mirror. Now I will spend the rest of my life trying to feel (not just see) that sense of wholeness (the Ideal-I) I see in the mirror."
The upshot? Once a child has gone through the mirror stage, he realizes that his sense of self will always depend on being seen and recognizable by someone else—the Other. As that baby gets older and starts yakking away, he'll use language to get into relationships with all sorts of other Others. In talking and developing relationships through language, that baby, now a person, develops a personality and (if he's lucky) maybe even a neurosis.
I know this is a really popular and maybe even overused term for theorists, but I still couldn't resist. And let's be honest: I totally up the ante on those other guys by making a distinction between "the big Other" (A) and "the little other" (a). An analyst really and truly has to understand the difference between A and a because the last thing he wants to do is come across as to his patients is as a—the little other.
By now you're probably cursing the day I was born (with an uncanny gift for language), but give me a chance to explain the difference. "The little other" is not the real other, it is projected by the ego and is a complete work of the imagination. Remember that Ideal-I? Well that's the same thing as "the little other." It's not real—it's made up.
I inevitably identify with "the little other" in a way that I never can with "the Big Other" because the latter is other people—not my divided self. The Big Other may be people I encounter in daily life or even the language I use, the conventions of social life, and all of the laws that control me. All of these things preexisted me, so they must be other to me as a subject—they cannot be part of who I am. Nonetheless, I must use the language and law of the Other in order to interact with people. Get it? Got it? Good.
The subject is all the messy emotional, mental, physical, and psychological stuff that makes a human individual a person. The self-awareness and autonomy of the I is never cut and dry. Why, you may ask? Because of the id and the weight of the superego. Because all of these other factors are mixed up all the time, I never designate an individual as a subject. After all, a subject is all divvied up into various parts (among them id and superego).