Irene Au: Body Languages of Interaction Design
Data driven design, is great, but lacks empathy. It becomes more analytical. True empathy go beyonds observation, because experiencing what others are experiencing in your bones is what true empathy is.
We can train our empathetic mind, through yoga and meditation. This is due to the mind-body connection. When your body gets stiff, these changes in the body can actually affect mood, expression, changes.
A study showed that using botox injection in depresssed patients to prevent them from frowning, actually increased their happiness.
Non verbal language, affect how we feel and how we think, and therefore affect how we design. Posture reinforces how we feel about ourselves. It can counter how we currently feel. I think it's an interesting note when we design for products that may change the posture of humans. It can project their feelings positively, or negatively on to the product.
http://ixda.org/resources/irene-au-body-languages-interaction-design