Conjunction Fallacy

Image created with Midjourney. Image prompt:
Image created with Midjourney. Image prompt: 2d minimal style illustration of the concept of the Conjunction Fallacy: A split image, on one side an individual working diligently at a bank desk surrounded by minimalistic bank architecture, on the other side the same individual managing a 'Third-World Foundation', with symbols of social responsibility and global impact subtly incorporated. Use a simple, monochrome palette with pops of color for emphasis.

The Conjunction Fallacy is a paradoxical concept in probability theory where the intuitive mind often favors the possibility of detailed, specific events over a general one. This cognitive bias has far-reaching implications, even in the realm of digital software product creation.

To understand this, let's break down the Conjunction Fallacy with three illustrative examples:

The Linda Problem

This classic experiment asked participants to rate the probability of Linda, a socially conscious former philosophy student, being a feminist bank teller versus simply being a bank teller. Despite it being statistically more likely for Linda to just be a bank teller, most respondents chose the conjunction (feminist bank teller) because it fit a more coherent narrative.

The Soccer Match

Suppose you're wagering on a football match. The likelihood of Team A winning is more probable than Team A winning with a score of 3-1. However, the added specificity may appeal to our intuition, leading us to bet on the less likely outcome.

The Stock Market

The probability of a tech company succeeding is generally higher than the likelihood of a tech company succeeding by developing a specific, revolutionary product. Still, we might be drawn to invest in the latter due to the allure of a compelling story.

How does the Conjunction Fallacy connect to the creation of digital software products?

Decision Making

Developers and product managers might favor complex solutions (specific scenarios) that solve many problems at once over simpler ones that address general issues. This bias could lead to over-engineered software, which is difficult to maintain and scale.

User Experience

In crafting user journeys, designers might focus on the specifics of a detailed user persona and neglect the broader user base. This can lead to a product that does not effectively serve the majority of its users.

Marketing and Sales

Marketers could be tempted to target a very specific niche (a combination of multiple factors) rather than a larger, more general audience. This could limit the product’s reach and overall market share.


In conclusion, the Conjunction Fallacy, while an innate aspect of human cognition, can lead to suboptimal decisions in digital software product creation. By being aware of this cognitive bias, we can make more informed decisions, design better user experiences, and implement more effective marketing strategies. Awareness and understanding of such psychological phenomena are key to creating successful digital products that truly meet the needs of the users and the market.