How UI/UX Design Influences Human Behavior

In the guest speaker session about how UI/UX design affects human behavior, I learned that good design goes far beyond aesthetics, it’s deeply connected to how our brains process information and make decisions. The speaker explained that our brains mainly operate in two modes: intuitive (95%) and logical (5%) which is what I've learnt in the book my uncle gave me "Thinking Fast & Slow" by Daniel Kahneman. The intuitive part is fast, emotional, and automatic, while the logical part is slow and analytical. This means that when people interact with a website or an app, most of their reactions and decisions come from their intuitive brain, not from deliberate reasoning.

One key point that stood out to me is that words are not “friendly” to the intuitive brain. Our intuitive thinking responds better to visuals, patterns, and emotional cues rather than long text. That’s why effective UI/UX design uses visuals, icons, and concise phrases instead of heavy paragraphs. It reminded me that users don’t read every detail, they feel whether the interface is easy, trustworthy, and appealing.

The speaker also discussed how our cognitive biases influence decisions. These biases come from past experiences and help the brain make quick judgments. For example, the scarcity principle makes people value something more when it seems rare or limited (“Only 2 items left!”). The social proof effect shows how we trust things that others already use or approve of like reviews, ratings, or user testimonials. Both can be powerful tools for increasing user engagement and trust in a product, as long as they’re used ethically.

Another interesting concept was the decoy effect, which shows how adding a less attractive option can make another choice seem better. I realized this is often used in pricing pages, the “middle plan” or “best value” option is designed to guide users toward a specific decision. Then there’s the paradox of choice, which explains that giving too many options can overwhelm users and reduce satisfaction. In UX design, simplicity is key meaning fewer, clearer options make decisions easier.

I also learned about the mere exposure effect, where repeated exposure makes something feel familiar and trustworthy. This highlights the importance of consistent branding, color schemes, and design language. Finally, the power of default showed how users tend to stick with preset options. Designers can use this insight to make the best or safest option the default, gently guiding user behavior without forcing it.

Overall, this session helped me understand that design is psychology. Every color, button, and layout choice affects how users feel and behave, often subconsciously. The main takeaway for me is that designing for the brain means designing for intuition which means creating interfaces that feel natural, reduce effort, and build trust without users even realizing it. I learned that successful UI/UX design doesn’t just look good, it thinks like a human brain.