The id is the pleasure center of our psyche, according to Freud. To Freud, it was the “dark, inaccessible part of our personality” (enotes reference, id).
Lady Macbeth represents the id because she tells Macbeth what he wants to hear and encourages him so he will kill Duncan and become king. Lady Macbeth thinks only of herself and what she wants. She is basically the equivalent of a child. She describes what she would do to a baby she was nursing if it fit her needs.
I would, while it was smiling in my face,
Have pluck'd my nipple from his boneless gums,
And dash'd the brains out, had I so sworn as you
Have done to this.(65) (etext p. 24)
This shows how completely heatless she is. She seems willing to dash a newborn baby’s brains out of it will give her what she wants.
Lady Macbeth continually encourages Macbeth until he kills Duncan, and then berates him for not doing it right (not leaving the daggers). She is his unconscious, and lives by her own.
Thank you soo much :) this makes sense now. This has helped me a lot, thank you for your time :D