26th June 2017

Your chatbot needs a personality

Mike Jongbloet
Head of Design and UX

It had been a long day at work. As I was about to leave I was sent a link to a chatbot. So I sat back down and started to talk to it. Forty five minutes later the office was empty. Except for me. Sat there, talking to a robot.

I recently gave a talk to 80-odd user experience practitioners at Mobile UX London. I started by asking for a show of hands on how sold everyone was on chatbots – were they more fad or revolution? Somewhat surprisingly for me the vote was about 95% revolution with a couple of lone hands for fad.

I was certainly more of the belief that they were a passing fad. They simply didn’t capture my imagination. They were missing something. That was until I spoke to the Channel 4 “Humans” bot. Then I realised there was a clear use case for them in marketing.

So what drew me in? Why was I at work talking to a chatbot, instead of at home talking to my wife? I’ve tested many chatbots and they’ve mostly been uninspiring. As I drove home I thought about this and summarised in a single word: it was personality that made the difference.

More than just dialogue

The premise of the bot is that you are talking to a synthetic human. The dialogue starts out simple enough, but then the bot goes haywire. The conversation very quickly spirals into getting to know each other, emotional pleas and moral choices. 

In the image below the far right screen shows a moment where the system detects that the bot has gone haywire, and asks you to either ‘Report’ or ‘Ignore’. I actually found myself deliberating over this choice as the bot pleaded with me to press ‘Ignore’.

It was engaging. It tapped into an emotional level of conversation in an impressive way.


The chatbot hype train has well and truly left the station and seems to be travelling at a steady 8 million miles per hour. They are popping up all over the place and we are starting to see some really smart and clever applications of the technology. As marketers, designers and product owners we need to think hard about how we differentiate our bots. “First to market” has long passed.

By thinking deeply about the design of personality and triggering an emotional reaction in your users you will provide a richer, more memorable experience.

What is personality?

Once I’d decided personality was the differentiator, I started to think about what personality actually is. I asked around a few people and came up with words like:

  • It’s an individual's thoughts, feelings, behaviours, actions, and interactions.
  • It’s what our character is made of. It’s what makes us unique and different from each other.
  • It’s impactful and memorable.

Impactful and memorable. Why wouldn’t we want that from our chatbots?

Think about someone you recently connected with. I mean really connected with. Not small talk and chit chat, but someone you felt a strong connection with. It might have been a new colleague, a friend or even a stranger. What was it that made that connection? More than likely it was their personality that matched yours and formed an emotional connection.

We need to design chatbots that form these connections with our users. Good conversation isn't enough. It needs to be meaningful.

Why is personality important?

In his book Designing for Emotion, Aarron Walter takes an alternate view on Maslow's hierarchy of needs in the context of product design. He suggests that functional, reliable and usable are the things our product has to have. This can be applied to chatbots as well. If a bot doesn’t work, is unusable or is unreliable and inconsistent, then it hasn’t got any chance of having impact.

Maslow's hierarchy of needs

However, even if it fulfils these categories that might not be enough for success. Aarron Walter said that products being pleasurable to use is how we can differentiate. In chatbots, pleasure comes from personality.

Will we as humans, with all the emotional complexity that brings, ever really connect with the growing army of straightforward and frankly boring bots?

By using personality to trigger an emotional reaction you provide a richer and more memorable experience. You make an impact on an individual.

How do you design a personality?

Personas are a well debated design output in our industry these days. Some people love them. Some people hate them. I think they’re a great tool for designing personality. 

When we’re designing a personality we get to turn the tables. We get to design a persona with the only limit being our creativity.

Base in research

It goes without saying that the design of your chatbots personality should be based in research of your target audiences. What kind of people do they hang out with? What kind of journals, papers or websites do they visit often? What kind of personality traits do they display?

Once you’ve got a good understanding of your audiences you can get started. 

The Five Factor Model

In the 1980s Lewis Goldberg, personality psychologist at the University of Oregon, developed the Five Factor Model of personality. It’s a model based on common language descriptors of personality and using it we can begin to map where our bot will sit on the five scales.

  1. Extraverted: assertive / sociable vs quiet / reserved
  2. Agreeable: cooperative / polite vs antagonistic / rude
  3. Conscientious: task-focused and orderly vs distractible and disorganised
  4. Neurotic: anxious and worried vs emotionally resilient
  5. Open: broad interests and cultured vs routined and narrow minded 

Is it an antagonistic extravert or is it polite, cooperative and sociable? By playing around with the different ends of each spectrum you can begin to develop the shape of personality for your bot.


Personality traits are defined as habitual patterns of behavior, thought, and emotion that form the prominent aspects of our character.

There are hundreds of traits that help to describe our character for example this list of 638 personality traits from MIT. Once we have a rough shape for our personality we can get more specific by giving it traits.

Whether or not we’d admit it we all have positive, neutral and negative traits so make sure your bot personality has a balance. I’d propose starting with three of each and taking it from there. Don’t go overboard though – the fewer you have the more focused and clear the personality will come across.

Tone & voice

By now you’ve built up a fairly detailed profile of a personality. Whilst we display our personalities through facial expressions, body languages and non-audible signs our chatbot has one main mode of communications - language. So, now we need to give it a voice.

How does your bot speak? I’ve found a good exercise to begin designing tone of voice is to take some simple phrases that someone might say and design how your bot would respond. 

For example if a human says “I don’t understand you!” how would your bot respond. Would it be blunt, funny and sarcastic as in the example on the left or perhaps more serious, respectful, friendly as in the example on the right.


This step is particularly important as it will form the core basis of your chatbot experience.


Finally, we can liken our bot to someone we can relate to. For example which celebrity is your bot most like? How old is it? What hobbies does it have? Whilst these steps aren’t essential they can help build a more thorough personality profile which will come in handy when writing the chat scripts.

Using your personality design

  1. Build your bot’s persona
    First use the steps above to design your bot’s personality. What you’re trying to build is a simple profile of the personality. Distill your work down into a persona which can be quickly understood by anyone on your team. 
  1. Use the persona when writing
    Next use this persona to write the scripts for your chatbot. Reference it whilst writing and regularly check your scripts sound like your personality speaking and not you. It’s very easy to fall back into the trap of being who you are every day, yourself!
  1. Test your narrative
    Finally test your scripts. Ari Zilnik, a designer who worked on the EmojiSalad bot. suggests borrowing a method from New Product Development to test scripts. He launched his chatbot and manually responded to users following the script. At the end of the conversation he broke back into “human mode” and interviewed them on their thoughts and reactions.

Be unique. Have impact.

You don’t want your chatbot to get lost in the sea of thousands of others. You want it to stand out and have an impact. Designing a personality for your bot is the first step to achieving this.

Designing a personality is a fun and creative task, so get started and good luck. I look forward to spending many more hours staying late at work because I’ve been charmed by a robot personality!

You can find the slides from my talk here