Tamas is one of the 3 mahagunas (the basic qualities of nature). Tamas means darkness and is associated with Kapha. People with a tamas domination tend to have psychological blockages and a lack of self-care.
Ayurvedic principles describe various qualities that define one's physical and psychological constitution. The doshas define one's physical body whereas the trigunas describe one's psychological makeup. Discover more about your personality through the trigunas.