"Demonstrating while making calls"

Am guilty of this habit also,I find myself "demonstrating"unconsciously,while making a phone call.Why have we cultivated this habit, even when the person is far from us,the demonstration usually occurs when describing,directing or explaining on the phone.
Do you demonstrate while making a phone call?

Hell yeah.
recall my mum on the phone on her knees with her father inlaw(grandpa)
On the fecking phone(landline days)
She shuld tank God no camera fones bac den

me i tink its just to express ur self