The Circle – wholeness, the experience of unity
The Square – stability, solidity, security
The Triangle – dreams, visions, goals
The Cross – relationships, integration
The Spiral – growth, evolution
You can take Arrien’s preferential shapes test in her book, available at her site: http://www.angelesarrien.com/products.htm
My favorite shape didn’t make the 5 universal ones. Look for a post in the future about this.