Some recent research has shown that our con­scious minds con­trols less of our inter­ac­tions than pre­vi­ously thought:

The researchers could pre­dict how around 70% of the stu­dents would rate an instruc­tor just by analysing the instructor’s body lan­guage in 30 sec­onds of sound­less video. […] The researchers were able to devise an algo­rithm that could pre­dict whether a call would result in a sale from only a few sec­onds of data. Suc­cess­ful oper­a­tors, it turned out, spoke lit­tle and lis­tened more. And when they did speak, their voices fluc­tu­ated strongly in ampli­tude and pitch, sug­gest­ing inter­est and respon­sive­ness. […] In an exper­i­ment involv­ing a 45-minute mock salary nego­ti­a­tion between stu­dents in a busi­ness school, [Alex] Pent­land says that by com­bin­ing sev­eral dis­play sig­nals from the first 5 min­utes of the nego­ti­a­tion, his team could pre­dict who would come out on top with 87% accuracy. […]

As a result of such exper­i­ments, the MIT group has iden­ti­fied a hand­ful of com­mon social sig­nals that pre­dict the out­comes of sales pitches, the suc­cess of bluff­ing in poker, even sub­jec­tive judge­ments of trust. These sig­nals include the ‘activ­ity level’, effec­tively the frac­tion of time the per­son speaks; their ‘engage­ment’ or how much a per­son dri­ves the con­ver­sa­tion; and ‘mir­ror­ing’, which occurs when one par­tic­i­pant sub­con­sciously copies another’s prosody and gesture.

The orig­i­nal Nature arti­cle is behind a pay­wall, hence the link to Over­com­ing Bias with their larger excerpt.