Author Aaron Sultanik observed that in Sellers's early films, such as "I'm All Right Jack", he displays "deft, technical interpretations pinpoint the mechanical nature of his comic characterization", which "... reduces each of his characters to a series of gross, awkward tics". Academic Cynthia Baron observed that Sellers's external characterisations led to doubt with reviewers as to whether Sellers's work was "true" acting. Critic Tom Milne saw a change over Sellers's career and thought that his "comic genius as a character actor was ... stifled by his elevation to leading man" and his later films suffered as a result. Sultanik agreed, commenting that Sellers's "exceptional vocal and physical technique" was under-used during his career in the US.