Grey suggests the use of curves instead of hard edges on counters, furniture, and cabinets to help nurture contentment and well-being. "The reason has to do with your peripheral vision and is linked to a primitive part of the brain called the amygdala," he says. "If you were to walk down a dark, narrow tunnel lined with sharp rocks, you wouldn't be able to think about anything except avoiding getting hurt. But if the same tunnel were lined with linen upholstery, you'd feel safe to daydream." Everything need not be rounded—"that gets very tedious," Grey says. "But if the key pieces and places are curved, that makes the body relax."