Effective mentoring ensures the progress of science

Manfred T. REETZ

(1. Max-Planck-Institut für Kohlenforschung, Muelheim an der Ruhr 45470, Germany；2. Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China)

Abstract Mentoring doctoral students and postdoctoral fellows effectively is a crucial responsibility of every professor worldwide because it ensures the progress of science. However, every mentor has his/her own style, which is determined by the personal temperament of the mentor in different cultural settings. Some international standards exist, which include ethical requirements. In this invited essay, I describe my own personal mentoring style without claiming that everyone should adopt it. I am convinced that effective mentoring is a two-way process between mentor and mentee. Consequently, I present guidelines for both mentors and for mentees. Mentors should allow mentees to voice their own opinions and ideas about research projects, and mentees should not be afraid to insist on these freedoms. A good mentor sends his/her coworkers to national and international conferences and symposia, and if this is neglected, the mentee should remind the mentor of this practice, which allows the mentee to present lectures or posters, and to form international networks for possible scientific collaborations. I have always asked my coworkers not to use a blown-up language for grossly exaggerating their results, neither in lectures, posters nor on websites, but mentors should likewise adhere to a tone-downed language. It is necessary that the mentor invests time in guiding the mentee on how to write optimal scientific papers, including the crucial choice of the title. Finally, I have always encouraged all coworkers to relax long enough on weekends in order to rejuvenate, which allows them to return to work in the laboratory with fresh enthusiasm and new innovative ideas. In the case of foreign postdocs, this ideally includes sufficient travel during vacation time to some German cities with visits to museums and possibly attendance of concerts or theaters, allowing them to learn the rudiments of German history and culture, knowledge that will be of use in their later careers. Vice versa, German postdocs in foreign countries, e.g., China, should not just engage in scientific research, but should also learn the basics of the culture of that particular country.

Key words mentorship; mentoring guidelines; ethical standards; career planning; chemistry; biology; biocatalysis; enzyme engineering

Introductory Remarks

It is a pleasure to accept the invitation to write an essay about mentoring, an important responsibility that has accompanied me throughout my 50 years experience as a professor for organic chemistry and biological sciences (website: kofo.mpg.de/en/research/biocatalysis). Before I started to write down my thoughts, I decided to check the internet to see what has already been written about this subject. Here, I cite only three typical publications[1-3]. I was a little surprised that the terms mentor, mentoring and mentorship occur thousands of times, and that mentorship is actually a science in itself with journals and monographs being devoted to this subject, pervading science, industry, economics, philosophy and ethics. And in fact, prizes have been awarded for excellent mentoring. Well, does it really matter whether yet another article appears? I cannot answer this question, others can do so.

Perhaps one should start by first seeing how mentoring and mentorship have been described. According to Wikipedia, the definitions[4]are as follows：

“Mentorshipisarelationshipinwhichamoreexperiencedormoreknowledgeablepersonhelpstoguidealessexperiencedorlessknowledgeableperson.Thementormaybeolderoryoungerthanthepersonbeingmentored,buttheymusthaveacertainareaofexpertise.Itisalearninganddevelopmentpartnershipbetweensomeonewithvastexperienceandsomeonewhowantstolearn.”

Over the years, I have guided about 125 doctoral students and 80 postdocs in my research groups in Germany (Marburg University and Max-Planck-Institut fuer Kohlenforschung in Muelheim). They came from all over the world. Statistically, about 15 coworkers with doctoral degrees came from China, and indeed no other single foreign country has blessed me with more postdocs. So how did I choose my coworkers? In the case of potential masters or doctoral students, I carefully studied the quality of their past records, but I knew that excellent grades is not the only important parameter. Therefore, all applicants were asked to come to my office for an interview so that I could learn more about their character. I especially appreciated those who were enthusiastic about research and expressed no hesitation in accepting risky projects. However, I remember one case in which the applicant continued to brag persistently concerning past record, and in fact this person never joined my group. Nevertheless, I took time to explain things as part of mentorship, and this scientist proved to develop a very good academic career elsewhere. In the case of applicants for a postdoctoral position, the situation was more difficult if he/she came from a foreign country, because a personal interview was not readily possible. In such cases, in addition to studying the past performance, including the subject of the doctoral thesis and of the published papers, letters of recommendation played an important role, especially whenever I knew the thesis advisor personally. In the case of Chinese applicants, my visits to China over the years has helped a lot in this matter. Since in the 1970s and 1980s, German universities did not have an effective funding system for postdocs, my group hardly had any such coworkers in those days. This changed fundamentally after I accepted the position of a Director at the Max-Planck-Institut fuer Kohlenforschung in 1991.

The Max-Planck-Society encourages Directors to consider truly innovative and novel projects, which means that risky research can be performed in addition to less risky subjects, knowing that sufficient funding is ensured until retirement at the age of 68. Of course, evaluations are made typically every three years. I made use of these opportunities immediately after leaving Marburg University and joining the Muelheim MPI.Oneoftheriskyprojectsinitiatedin1994/1995wasdirectedevolutionofstereoselectiveenzymesascatalystsinorganicchemistryandbiotechnology. Inspired by the paper of Pim Stemmer on DNA shuffling[5], I speculated that perhaps protein engineering could in principle provide a non-ceasing source of selective and sustainable catalysts, a dream! It was not only scientifically risky, but also required significant investments in establishing a molecular biological laboratory and acquiring robotic equipment in a chemical institute. By 2002-2004, this adventure proved to be successful[6]. Around that time, other groups joined efforts in this novel and exciting way to obtain stereoselective catalysts, which caused me to put all efforts and funding into this new research area. Due to the growing interest (and competition!), I focused on methodology development and the need to understand mutational effects on a molecular level.Therefore,ingroupmeetingsnewideasformakingmutagenesisandscreeningfasterandmorereliablewerediscussedandimplementedexperimentally[7-8]. I also realized that scientists can learn from directed evolution, allowing us to identify and understand the intricacies of enzyme mechanisms. This led to decisions for mechanistic projects, some in collaboration with top theoreticians and protein structural experts in Germany, China, UK, Sweden and Spain. Today I believe that this decision was clearly correct, rather than just applying suboptimal mutagenesis techniques and strategies using different enzymes. Of course, following advancements of semi-rational directed evolution methods in our group, different enzyme types were tested. But which ones? The choice depended on the question whether catalysts for challenging synthetic transformations could possibly be evolved[7-8].

Several dozen former doctoral students and postdocs in my group became professors in Germany and elsewhere in the world, e.g., in China. Others gained good positions in industry, and a (very) small number founded their own companies.

My Personal Mentoring Style

It is probably true that every professor has his/her own style when mentoring coworkers. I do not wish to dictate anything to anyone, rather, everyone who reads these lines should make their own decisions. After all, scientists around the world, including the very best ones, work in different countries with different traditions and different science structures. Of course, a few essential characteristics that we all know are common to all systems.

Long ago I realized that mentoring isnota one-way process in which the mentor simply tells the mentee what to do, expecting that in this way enough will be learned for an excellent career in academia or industry. As the above definition of mentorship indicates,thementorcanalsolearnfromthementee. Since I always wanted our projects to be as successful as possible, I routinely made sure that ethical standards are maintained, and that:

• Coworkers should not have the feeling that they need to automatically agree with me just because I am the boss who happens to finance the research and who plans the project. Rather,theyshouldnotbeafraidtovoiceadifferentopinion,iftheyfeelso,whendiscussingscientificissuesinourprojectssuchasinterpretationofresults,controlexperiments,reproducibility,ideasonenzymemechanisms,decisionsregardingthenatureofsubstrates,andsoon. Mentees should, of course, also be consulted when deciding if a project should be terminated or extended.

• Coworkers should have sufficientfreedomtodevelopandimplementexperimentallytheirownideasinagivenproject, which has to be coordinated with the group leader. As an example, one Chinese postdoc was supposed to invert the stereoselectivity in a cascade sequence, but when it became clear that it was not likely to work in that particular case, he suggested that his research direction should be switched to methodology development. I agreed, and that decision turned out to be correct, resulting in triple code saturation mutagenesis (TCSM), an exceptionally efficient tool in directed evolution[9-10].

• In all cases,carefulandcompletedocumentationofallpositiveandnegativeresultsofallexperimentsinlabjournals(hardcoverorelectronic)ismandatory. At the Max-Planck-Institut fuer Kohlenforschung, hardcover lab journals, which are registered and carry the name of the researcher, are provided to all coworkers with their registered names, and my group adhered to this rule. Nowadays the institute utilized electronic lab journals.

• When holding lectures in the group or at conferences, or when presenting posters, coworkers shouldavoidoverblownstatementsleadingtogrossexaggerations, i.e., a self-critical, tone-downed language needs to be practiced, in which important results of competitors are amply cited. Obviously, this can only work if the mentor himself/herself abides by these essential standards, including the avoidance of exaggerated claims on his/her website. Following a lecture by a coworker, the mentor should provide his/her assessment, but not in the presence of the other coworkers, rather in a “4-eye” discussion, pointing out the positive aspects, but also possible negative ones that call for correction. As an example, I had to hold such a conversation with a coworker who failed to acknowledge the contribution of another group member, a rare situation.

• When writing a paper, all of the involved authors should remember the above bits of advice concerningproperandacceptablelanguageusage. Moreover, the title of a publication must be chosen carefully, and it should not be too long[11], but it should attract the attention of potential readers, reviewers and editors. Many suggestions have been made on how to write optimal publications[12-13], and boring ones which help to avoid mistakes[14]! While I do not agree with all of the opinions in some of these works, it may be worthwhile to take a look. An article onpublicationsuccessinbiology[15]may also be of interest to some readers of my essay.

• If anerrorinapublishedpaperhas been discovered by the authors themselves or by someone else in the group or by a scientist from somewhere else, then it the responsibility of the coworker(s) and the group leader to inform the editor of the respective journal as soon as possible. As a glance into typical journals reveals, such corrections often involve analytical mistakes or insufficient citations. In the extreme case, because someone cheated with thought-up data, immediate retraction is necessary (which fortunately has not happened in the Reetz group); I maintain that such a step is not a “noble” gesture as sometimes stated, but should be a routine act.

• The mentor should not forget to emphasize to the mentee thatexcellentteachingisanotherprerequisiteforasuccessfulacademiccareer.

The above points are the fundamental pillars of how I have mentored my doctoral students and postdocs. Most chemists/biologists will probably agree, although different opinions and style may well occur with respect to one or more individual points. But experienced scientists know that things are more complicated.Thebasicquestionishow“top-quality”sciencecanbeidentified. What are the parameters that define truly innovative research? I have asked many colleagues and a number of policy-makers, but I have never heard a definitive answer. Over the years, I have served on various boards and committees that assess grant proposals or decide on awards or promotions to professorships, in addition to acting as a reviewer of countless submitted papers to various journals. In all of these situations, the above basic question pertains. It decides over careers. I have often experienced that the Hirsch-factor was used as a guide, but I do not agree that it is a reliable parameter (my h-factor (Google) as of October 2020 is 119, but this high number does not excite me at all). Indeed, the Nobel Laureate Richard R. Ernst has succinctly stated that such bibliometric measures are meaningless[16]. I wish to recommend his one-page essay. Another parameter that is often used as a quality assessment is the number and frequency of papers that a candidate has published in so-called high-impact journals. This seems more reliable, but difficulties arise here as well. Imagine you are a group member or the leader thereof, and you want to cite an appropriate review, two options being possible, an article in a high-impact journal or a review in a medium-impact journal. If the former has a higher quality, the choice is clear. But what happens if the latter is actually superior because it contains more intelligent and critical analyses with more balanced citing? I am afraid that many (or most?) scientists would not choose the superior review. Could this be one of the reasons why such journals are cited so often? I myself have no solution to the problem of developing an effective assessment of a researcher’s contribution(s), but the least we can do when faced with making decisions in boards or committees is toreadandcomparesomeofthepublicationsoftherespectivecandidates, rather than just looking at the names of the journals or simply considering h-factors. This is rather time-consuming, but in the spirit of fairness and efficacy, we all need to invest ample time in such efforts, as R. R. Ernst has stressed much more impressively than I am doing in my present essay: “Verysimply,startreadingpapersinsteadofmerelyratingthembycountingcitations[16]”. Younger scientists should be considered more often as reviewers, and they should express their willingness to participate in such work.

So what do these remarks mean for mentoring? Both mentors and mentee need to be realistic. Striving for optimal scientific results is an obvious goal, but a self-critical analysis when writing and submitting papers is necessary, and only truly excellent results should be considered for top journals. Submitting sub-optimal results of a given project to the highest impact journals, while speculating that rejection can be followed by submission to a lower impact journal, is not a good idea. This strategy constitutes a huge waste of time for everyone involved, including the reviewers and editors.Ihaveobserved,however,thathighlyinnovativecontributionsfromsomecountries,includingChina,sometimesoccurinmedium-orfairlylow-impactjournals,whicharethennotcited(orread)asoftenastheydeservetobe. I have no real solution to this problem. In any case, mentors should send their doctoral students and postdocs more often to national and international conferences where they can present short lectures or posters. Such meetings also constitute ideal opportunities for international networking with the goal to collaborate in a transdisciplinary manner (but favoring each other in reviewer reports is unethical!).

Menteesshouldnothesitatetopointouttheirwishestothementors. The direct contact with competitors is essential, although currently difficult due to the corona-crisis, but that will change to the better in due time. The world-wide scientific community offers a huge number of conferences, symposia and other types of meetings for ample discussions and personal contacts. Personally, I am skeptical about other types of communication that have been established in commercial internet-forums for posting scientific views and opinions, often superficially in single-sentence format (some being organized?). I have never twittered (and I am not alone in my clearly critical view of such practices[17]), nor have I asked my coworkers to do so, although some top journals offer this possibility. Here again, every individual should decide himself/herself in this issue.

Finally, I wish to address yet another mentoring practice that I have always considered to be important.Ifamentorseesindicationsthatamenteehasstartedtohavepersonalproblems,itistimetohaveadiscretetalkwithhim/her,cautiouslyofferinghelp. It may be necessary to lower excessive “pressure” that may rest on the person’s shoulders, which produces feelings of fear. Working 7 days a week, 12 hours a day, is in my opinion too much. Humans need ample time to rejuvenate, because this lets them return to work with new energy, and new ideas for innovation! Certainly, at least Sundays should be completely free, with no e-mail-activity with the group or group leader for scientific reasons. In the case of parenthood, more free time is needed. During my own doctoral studies (1967-1969), all group members were expected to work until noon on Saturdays, leaving one and a half days for leisure, which I think is appropriate today as well. Reasonable exceptions in certain cases can be organized. Relevant is the number of days taken for holidays. I have noticed that especially Chinese postdocs keep their vacation days at a bare minimum, because they want to collect as many promising results in the laboratory as possible. Some mentors may favor such an attitude. But in my analysis, I do not believe that it is optimal for science, nor for the career. The number of vacation days in Germany is quite high, and perhaps not all of them need to be taken, certainly when working in science research (I have never utilized them fully, despite the fact that my wife and I had 4 children). But it is important that Chinese coworkers (and other foreign group members) get to know Germany more closely by travelling to some major cities, visiting museums, enjoying a few concerts and theater events, thereby learning our culture and history at least a little bit.Yearslater,followingthereturntoChina,theGermanexperiencewillprovetobevaluable,beitinacademiaorintheindustrial/economicsector. I guess my postdocs often made compromises after discussing the situation with me, which is fine, although I usually encouraged them to take a few more vacation days. In turn, I believe that gaining postdoctoral experience in China by young German chemists and biologists is an attractive option, especially with the opportunity to do some travelling for getting to know at least the rudiments of Chinese culture and history. In the 21st century, such experience is likely to be a significant advantage in a subsequent career.

Conclusions

The above brief treatise offers a number of guidelines for mentors and mentees, which I personally think are especially important. I do not want to repeat them here in detail, nor do I maintain that everyone should adopt them. Every mentor and mentee has his/her own style. I myself believe that it is an essential responsibility of every group leader to provide to all coworkers tips and guides on good practices in research, including ethical issues[17-20], as well as the plea to avoid blown-up self-presentations in publications, lectures, posters and websites. With today′s fierce competition for jobs, positions, financial support and awards, some mentors put maximum pressure on the mentees to work long hours and days, but I personally believe that this may be counter-productive. Humans need sufficient free time to rejuvenate for generating new ideas in research projects, which in turn ensures continued excitement and fun in science!

Edited by Prof. Zhoutong SUN from Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences(本文由中国科学院天津工业生物技术研究所孙周通研究员编译)