Mitt Romney has the very bad nonverbal habit of not using his hands enough or as well as many politicians with much less experience. This adds to his relative inability to develop rapport with the masses and detracts from what pollsters quantify as "likability". From a body language standpoint this is no surprise. It also makes a person "feel" less trustworthy. In fact, if a person suddenly stops using his hands/arms as illustrators during a part of a speech, conversation, deposition, testimony, jury selection, etc. - particularly when they were displayed before and after - this is highly consistent with elevated anxiety (since Mitt appears to have forgotten his host's name - note how he addresses him as "Mr. Leader" at the 0:01 mark), and depending on the other nonverbals, a possible indicator of deception.
Mitt Romney chronically underuses his hands/arms. Many speech coaches from years past, with no scientific data would routinely give such advice based only on anecdote and personal bias. Certainly hand/arm illustrators can be over-used or inappropriately used too. Enter Ed Miliband ....
The leader of the United Kingdom's Labour Party, Ed Miliband, throughout much of the first portion of this video does his best Angela Merkel imitation and positions his hands in a prominent low and classic conventional steeple (see: Analysis #901: The Over-Used Steeple - Backfire in Berlin). While this MAP (manipulator, Adaptor, Pacifier) body language does project authority and power, it must be used judiciously. Most people over-use it (a' la the German Chancellor) and thus it backfires and sends signals of arrogance and condescension. It is best used as a scalpel and choreograph exactly when to display this nonverbal - at key moments in a speech, negotiation, conversation, etc.
Analysis # Mitt Romney's Response to Supreme Court's Decision on "Obamacare"
Analysis # 913: Low Confidence, Low Trust and Demure
Analysis # 2062: Mitt Romney in London Speaking out the Side of His Mouth - Anxiety-Insincerity or Worse
Analysis # 2052: Dialing Up Empathy and Sincerity - Mitt Romney & Barack Obama's Response to Aurora, Colorado "Batman Shooting"
Analysis # 1555: Ann Romney Hits it Back Over the Net to Hilary Rosen