The Gestalt principle of Similarity is one of the four Gestalt principles and it focuses on how we group objects together based on how similar they appear. The concept works when our brains create recognizable patterns based on a shared color, shape, size, texture, or a combination of vision and touch, then group them together.
An easy way to think about this is when an artist you know is about to release a new album, but starts with a couple of singles. We like the singles and the artist, so we group the album together as being a good one and we get excited to buy it. This same concept can be applied to your home or office, and the individual rooms in it.
To apply the Gestalt principle of Similarity to interior design, approach the rooms and your home as a whole with a “theme.” Our brains like to create order, and one of the quickest associations we make is to find similar objects and connect them together, creating vignettes that tell a story about a space.
If you don't want to take a themed approach, you can use the same finish for the furniture in the home. This creates a cohesive look from room to room and the similar furniture finishes connect the vignettes and tell the story of your space.
Items with dissimilar characteristics cause our brains to perceive them as belonging to different spaces. This can make a small space like a studio apartment or bedroom feel cluttered and chaotic, and it can have the opposite effect in large spaces.
In open floor plans, this chaos can help create invisible boundaries by separating the areas so each one can serve its own purpose. A carpet over hardwood floors for a sitting area interrupts the continuous flow of the boards creating the illusion of a separate space.
These interruptions are how to transition the use of the room or space naturally while bringing in a new color palette or aesthetic, all while using the Gestalt principal of Similarity. Here's how it can be applied to a few types of rooms.
Living Rooms
The rule of Similarity in your living room helps express your personality and sets the mood for relaxation or focus by choosing a color scheme like relaxing blues or neutral whites.
Decor that features your preferred colors should include the art on your walls, curtains, the fabric or upholstery on your couch or the accent pillows and throw blankets. The palette can be carried through coffee table decor, bookends on your bookshelves, and area rugs.
Couches are the focal point of the living room and do not need to match since the similarly colored items scattered around will be seen first. The key to similarity is matching elements throughout the room, not that every item needs to be the same color or use a monochromatic color palette like you’d see with color drenching to make rooms feel more expansive.
A blue color scheme works if relaxation and quiet hobbies are your vibe including a rug in a neutral blue-grey tone, paired with jewel-toned blue couch pillows, a lamp with a light pastel blue shade, sea-themed coasters on the coffee table, and extra seating with bold blue seat cushions.
Complement this with art featuring blue tones including nature-based imagery of flowers or ocean scenes, or modern art with blue marbling or prints of pieces like the Blue Horse series by the German Expressionist Franz Marc.
For a living room filled with conversations and activities, choose stimulating warm tones like yellows or oranges as the primary colors to sprinkle throughout the room, and accent walls or visible decor in pink to help lower aggression and help everyone feel calm so they can participate.
If you’d like to incorporate multiple colors so the room feels bright and full of energy, create a theme. A “sunset” color theme may be red, orange, and yellow, but could be accented with pinks and purples. These analogous colors share a warm hue because they are next to each other on the color wheel and will be perceived as similar.
Peach colored roses can be placed in a light pink vase on a coffee table next to books with purple covers. A warm orange throw blanket can be folded on the couch with art in matching frames on the surrounding walls. The art can feature lavenders, pinks, and oranges. The principle of Similarity will group these items together because they share the sunset color story, resulting in a cohesive look for the room.
If you would like to make creative choices with colors or textures in the room but are worried it will make the room seem chaotic and too busy, look for another aspect that the item shares like their shape.
A square or rectangular-shaped coffee table and side table will be associated with the rectangular wall art in the room in their boxy frames, as well as the rectangular TV. The art pieces are more similar to each other compared to the tables, as they share both color and shape.
Bathroom
The rule of Similarity can be applied in your bathroom by incorporating biophilic design throughout the space to create your own oasis for self-care and relaxation. Exposure to nature may help to relax the mind and body, and this may even apply to artificial scenes with colorful flowers, forests, mountains, or patterns reminiscent of nature like blue splashes that look like ocean waves on your shower curtain.
The natural humidity in your bathroom also makes it a good home for real plants like the low-maintenance ZZ Plant, Pothos, Snake Plants, and Scindapsus, which thrive in rooms with higher ambient humidity due to their tropical origins. Best of all they only require weekly to biweekly watering.
Plants also have the additional benefit of being living air purifiers while the space relaxes your mind. Nasa studied the purifying ability of plants and published which ones work best based on their research in pages 17 - 21 of this study.
A next step is to paint all the walls or one accent wall in nature-based colors like cooling light greens or blues, or a tint or shade of white with blue, green or purple undertones. An additional way to incorporate biophilic design and follow the Gestalt rule of Similarity is by using stone in the flooring or countertops including marble, slate, and granite.
The cool feeling of the stone will be offset with the warmth from the wood in your cabinetry and wooden frames housing nature-inspired decor like photographs, paintings of the beach, or dried flowers.
Last is to select the right fabrics that bring natural textures and materials like cotton or linen hand towels. The larger bath towels can be tones of green, brown, or blue. Now pick rugs in matching or complementary colors and you have used the Gestalt rule of Similarity to create a nature-inspired color scheme in the bathroom.
Each element in the bathroom echoes something found in nature, or is directly found in nature from the walls and flooring to the smaller details in your decor.
Office
The rule of Similarity in your office makes the space as easy on the eyes as possible by using similar colors and shapes throughout the room. The goal is to try and reduce distractions from the work area. To do this, make the actual workspace including your desk dissimilar to the rest of the room by creating a focal point.
This way you and anyone in your office remains focused on the workspace as everything else will blend into the background. This can make it easier to not drift off during meetings and to stay on task vs. having your eyes drift around while you need to concentrate.
The 60, 30, 10 rule can help here. 60% of the items in the room should share a common theme or color to create a neutral background, 30% are complementary functional items like additional lighting, mirrors that can reflect light and help you spot-check before important meetings, or toolboxes to organize your equipment. The workspace is the final 10% of items and focal point, with its own organization and color scheme.
To start, paint the walls in neutral colors like greens or blue-greys and include an accent wall behind the desk. This opens up your design options as the natural break caused by the accent wall helps to reduce the matching or alternating colors of the furniture and your desk. Use a darker shade of blue like navy or a deep forest green to balance the space while keeping it looking sophisticated.
To build up your background, look for frames or display cases in a similar finish in black, white, natural wood, or metallics that match the storage and shelving in the room. This ties your diplomas, awards, or wall art to the rest of the room, makes the room feel less cluttered, and creates a blended background based on the principle of Similarity.
The pieces inside the frames can be dissimilar and provide pops of color in different sizes helping to make the room feel less monotonous. The shared frame type and color that echoes other items in the room allow them to be grouped and serve as decor and not a distraction. The next step is to mount the frames at similar heights throughout the room.
Line up the top borders of the frames to create an imaginary horizontal line. Our brain creates the horizontal lines based on the principle of Similarity because the decor appears to have a similar perceived height and a shared color scheme creating a horizon line.
Fun fact: Navy blue was found to be the most calming from a study done by GH Smith in Sussex. And the world’s favorite color project which interviewed 26,000 participants found that saturated teal is the most popular color. Both of these colors can be used in the office color scheme above while following the Gestalt rule of Similarity.
By using our mind’s tendency to group similar items together we can make rooms and decor items feel balanced vs. chaotic, and the room more comfortable. The Gestalt rule of Similarity can be applied with shapes, colors, textures, and anything else that our brain can group together and create a feeling of familiarity.
