Several academics recently published an interesting paper with a wicked title: Chameleons bake bigger pies and take bigger pieces: Strategic behavioral mimicry facilitates negotiation outcomes (available as a PDF).

The paper concerns two experiments they undertook to investigate the effectiveness of mimicry. It has long been believed that, in business and social contexts, when you mimic the postures and gestures of the person with whom you are speaking, it improves the process of building rapport and trust, which leads to more effective interpersonal interactions, with positive overall effects on negotiations.

From the abstract:

Two experiments investigated the hypothesis that strategic behavioral mimicry can facilitate negotiation outcomes. Study 1 used an
employment negotiation with multiple issues, and demonstrated that strategic behavioral mimicry facilitated outcomes at both the individual
and dyadic levels: Negotiators who mimicked the mannerisms of their opponents both secured better individual outcomes, and
their dyads as a whole also performed better when mimicking occurred compared to when it did not. Thus, mimickers created more value
and then claimed most of that additional value for themselves, though not at the expense of their opponents. In Study 2, mimicry facilitated
negotiators’ ability to uncover underlying compatible interests and increased the likelihood of obtaining a deal in a negotiation
where a prima facie solution was not possible. Results from Study 2 also demonstrated that interpersonal trust mediated the relationship
between mimicry and deal-making. Implications for our understanding of negotiation dynamics and interpersonal coordination are
discussed.

In my experience, mimicry does indeed work – but only when it is not obvious!

As the authors noted:

It is important to point out that across both studies, none of the participants who were mimicked noticed that their opponents were copying their behaviors, suggesting that the effects of being mimicked occurred automatically and unconsciously.

The flip side is that if the participants who were mimicked realised what was occurring, it may have had a negative impact; that is, it may have made them mistrust the person/process, for fear of being manipulated.