Writers in these three fields take different paths on how to deliver a particular message to their audience. Writing in the humanities involves more of interpretation of human experience as well as others. A thesis statement is essential in this field because of trying to persuade someone to read and understand your argument and point of view.
Writing in the social sciences includes trying to prove a theory and thus includes more observations and evidence by writers in order to help achieve that purpose of making something credible. A hypothesis must be included because its a prediction about what you think will happen in a particular experiment and then after you conduct the research for it and try to prove it, you usually say if your hypothesis was right or wrong based on what you did. You write a hypothesis, conduct research, and try to prove a theory based on observations to try and answer a question are the main takeaways from writing in this field.
Writing in the natural sciences is pretty similar to writing in the social sciences and even in the humanities in terms of doing research to try and answer a particular research question. With natural sciences, it is about more scientific research and different methods of observation being used.
Although the overall field of study is different and there are different techniques used to write in these three fields, the overall context is similar in terms of needing to write a hypothesis and prove a theory using many unique forms of research. Without research, writing is almost impossible no matter what you are writing about, and I took that away from reading more about these.