Previously, Aitken’s subject matter has been primarily concerned with a navigation of an interior, metaphysical territory. However, his latest work has begun to look outwards more, encompassing wider issues and world events. Consequently, these images have begun to reflect an increasingly emotive space where tensions and anxieties found in the outside world have begun to be explored.

In these works the natural world, anatomy and evolutionary theory have been influential, and Aitken has become increasingly interested in representing the physical appearance and structure of the human body. In these works, silhouetted figures have acted as motifs that convey metaphorical topics of both a religious and secular nature.

Most recently, an ongoing series of paintings and drawings based on heads have marked a return to a more expressive mode of working.