The Spock/Playing With

Basic Trope: An intelligent, stoic person, generally rounding out the Power Trio.
 * Straight: Steven is an intelligent, seemingly emotionless man, who acts as a contrast to Kyle and Mark.
 * Exaggerated: Steven has absolutely no emotions and does nothing before calculating all of the possible outcomes.
 * Justified: Steven comes from a race where pure logic is emphasized, and emotions demonized.
 * Inverted: The McCoy
 * Subverted: Steven was played up as the Spock, but is less intelligent and/or more emotional than he seemed.
 * Double Subverted: ... But it turns out that Steven was roleplaying as someone less intelligent/more emotional than himself.
 * Parodied: Some values of Straw Vulcan played for laughs.
 * Deconstructed: Steven's stoic attitude leads to people calling him cold and ruthless, despite the fact that he's supposed to be the good guy.
 * Reconstructed: Eventually, though, the people that matter in the story respect him as intelligent and a needed logical facet to the group.
 * Zig Zagged: Steven is the Power Trio in the form of one person, due to either being a Mood Swinger or having a Split Personality.
 * At first Steven appears to be The Stoic, but then he is shown to have wild emotions until someone tells him to get a grip. Then he reverts to his logical side, but still retains a spark of emotion that allows him to make decisions based on his instincts at times, but only after going over them logically ...
 * Averted: Steven is just as intelligent and emotional as those around him
 * Enforced: "We're filming Star Trek."
 * "We need a character to be the other morality side - we already have one who's emotional and one that's sort of in-between."
 * Lampshaded: "Oh, another organic computer with legs. How dull."
 * Invoked: The Big Bad uses his knowledge of Steven's method of solving problems to give him a situation with an extreme moral dilemma where all the sides are equally logical.
 * Defied: Steven manages to look on all sides of the issue, both emotional and logical.
 * Discussed: "He's really stoic, isn't he? He's always butting heads with Mark."
 * Conversed: "Why is there always a guy who runs on pure logic?"

Captain, the most logical course of action would be to go back to The Spock.